helpme15 on "Random blood stains but no bites"

I think am I going to completely loose my mind so any help would be greatly appreciated! Back in August I had what appeared to me a low infestation, meaning that I was the only one in my house getting bitten and I never actually saw any bugs but my reactions to the bite were very severe. Large itchy and burning welts that left scars...So I had the placed treated, twice because that it was the PCO recommended. That seemed to work because I have had no bites since August...
Flash forward to now and I am noticing some spots that look like blood about once a week on my sheets but I have no bites and neither does my boyfriend. Is it possible that my reaction has changed so dramatically? I am highly allergic to all insect bites so to me this seems unlikely.
So I have no idea how to precede... Call the PCO and have him treat my place again? Wait ?
Any advice would be appreciated as I think I am going crazy!!