STD contamination fears

I’m new to this page and have been experiencing some thoughts which I think can be associated with health anxiety or OCD I recently participated in sexual intercourse with someone and I can’t get the thought out of my head that I contracted an STD The one night stand was about 7 weeks ago and it was “protected” however, I can’t shake the thought that I have and STD/HIV I’ve tested 4 times since the encounter and they’ve all come back negative however every time you read something on the internet it says you may have tested too soon! Now I find myself wondering if I have bad results. Also, I find myself wondering if every physical aliment I feel is related to an std that hasn’t shown yet. Has anyone experienced anything similar?

I’ve been feeling the urge to avoid intimacy or purposefully engage (for reassurance that I won’t give into a compulsion) because of intrusive thoughts and fear that I’ll “check/test” my reactions. My OCD is making me so scared that I’ll purposefully think of a child and try to see if I like it. It’s so complicated but I guess I’m mentally checking if I would mentally check during intimacy. I’ve even envisioned myself checking and it’s making me so nauseous. I know it’s a compulsion like any other but the sound of “touching yourself to the thought of a child” sounds atrocious and vile. I’m terrified I’ll automatically start checking next time I am being intimate. I truly feel so worried. If anyone has gone through something similar, I’d appreciate hearing your experience. Or if anyone has any advice?

Trying not to seek reassurance, but rather connect the dots on my OCD and possible reasons as to why I am the way I am. I have severe OCD (or at least I hope I do) mainly surrounding POCD. I've had symptoms of OCD the majority of my life but this theme has come up more recently. When I was a kid, and i'm talking 6-7, I was first exposed to some really gross adult content online. It was introduced to me by a friend of mine around the same age of me. I saw some really disgusting things that a 6-7 year old should definitely not see. This was not a one time occurrence, as I had been exposed to taboo topics online years to come after that, such as the same friend introducing me to Omegle... And i'm sure you can imagine how that went, theres a lot of genuinely disgusting human beings on there. Coming back to the reason for making this post; is it possible to early exposure to this content could be one of the reasons I struggle with POCD? It genuinely scares me to death because you hear that real p*dos dealt with simular situations when they were kids, so thats kind of making me feel that this could be more than OCD, and I could be a genuinely bad person. My POCD feels so real, that at times i'm fully convinced its not OCD. Sometimes I can't even distinguish the feelings of attraction between a younger person and an older person, except for the feeling of anxiety and fear. Its really hard to explain without going into detail, but it just feels so real. Some feedback on this would be great, thank you all.