Hello everyone.
If someone could help me with my problem, I would appreciate it very much as this is just killing me.
After moving to another room (I am renting a flat with one more person) last year around the same period of time October / November I had a problem with something that was bitting me. This is very weird but it all started happening after a week when a guy joined our team at work. He sit near me and not to sound horrible he is not a clean person to the point that recently he had a company clean his one bedroom flat for 8 hours and they had 36 huge bags of crap. Not sure why you would share that with your coworkers by anyway. It first appeared on my lower body 3 bites apart from each other by 1 inch. Then mainly on my legs. Itching of course. Sometimes in a group spaced around an inch or just single ones. Of course I stumbled upon the bed bug problem on internet. Haven't found any evidence in my room that I have them not even a single one also no sign of blood on my sheets. As we know it doesn't mean they are not there. So I decided to tell my LL and call a pest control. The guy told me there is no problem, couldn't find any bedbugs but he used the pesticide anyway in the entire room.
I bought a mattress cover, a zip cover for the bedding and the pillow. The bites stopped.
This year the horror started again. I am getting bites and this time is on my legs and upper body mainly back. Everything started around August. I find this bites in different times of day but mainly I wake up with something itchy. I don't want to call the pest control again as they will probably not find anything like the previous time and I want to deal with the thing once and for all. So please bare with me I will write down in points as it will be easier for me and if anyone could confirm that this could be bed bugs or what should I do I would appreciate it. BTW I live in UK.
Here goes:
1. I am aware of the bites usually in the morning like today I have woken up at 6am with my back itching.
2. Bites are in groups and very itchy, sometimes when I scratch the bite that may seem just one you get two small dots.
3. They appear every 2, 4 weeks and I think there is more each time (last one is just crazy)
4. I check everyday the bedding and around the frame but there is no evidence.
5. I still have the covers for mattress, bedding and pillow.
6. I have made CO2 traps I have 4 of them ( no bed bugs trapped after a week)
7. I have been using diatomaceous earth for 3 weeks now probably too much as you will see in the pictures.
8. The bites are itching when you touch them.
9. I have used a steam cleaner to clean the carpet that is in my room and also the bed frame and each crevasses I could find next morning I had found bites on my legs.
10. No evidence at all of bed bugs or I am blind.
11. Nothing in the traps, I have two of them near the bed frame and one not that strong under the bed.
12. My flat mate has no bites at all.
13. My bites are itchier on my legs then on my back.
14. I don't travel at all. My life is: work - home 
15. At work I am sitting and scratching my legs as I think there is something but I haven't seen a single bed bug.
16. One day at work I have noticed 2 red dots on my knee that were not there in the morning, very red, not itchy at all and not bumpy. In the evening (4-5 hours later) those two dotes transformed to an itching hell and looked like mosquito bites.
17. Every weekend I spend my time looking for those bastards in my bed frame.
Here is a twist.
2 weeks ago we have moved the guy that was sitting besides me to a different place and my friend that sits now besides him found a flea on his arm exactly the same day he moved there. Last week I am sitting at my computer and I felt something on my leg I looked and there was something brown. I caught it and my friend told me it is a flea. Later that day I have noticed 2 bites in the place I have found the flea that were itching like hell. The only person as I know that gets bites is just me so that is why I was thinking it is at my home. After that I have 2 flea traps in my room but they have not caught any thing.
That is basically it. I am very sorry for how long it is but I am so confused and no one seems to know how to help me.
Here is a gallery of images I have taken. Any input would be very appreciated. What can I do? Are those bed bug bites or maybe fleas?