Me and a girl had sex early morning on the 8th. I wore protection and only had actual intercourse for less than 5 minutes. The condom never came off, and I never came. In fact, I couldn't keep it up because of the fear of getting her pregnant. When I pulled out and said I'm done, the condom was still on. After that, we ended up finishing ourselves off. I don't remember any exchange of my fluid to her, but there could have been. She had her period on the 15th, but she thinks she was late. We took multiple pregnancy, all came out negative. On the 26th we got sick of being paranoid, so we went to a doctor, and both her urine test and blood test came out to be negative. We are still paranoid, because she has been showing some signs. I don't know if these are paranoia or she is actually pregnant.

My reasoning, research and logic is what is keeping us both sane. If she was conceived on the 8th, she would have had vaginal bleeding 7-10 days later, around the 15th (as I've read). A blood pregnancy test will be very accurate at about 12 days after conception. If this was indeed her period, a man's sperm can stay alive in a women's body for up to 7 days, so the day she had her period, my sperm would have died. If this was vaginal bleeding due to pregnancy, the blood test would have shown a positive result 18 days after conception. Furthermore, she said she ovulated yesterday, but then again, that could be dillusional.

So, in all of this, is my logic correct, and she and I are both hypochondriacs because we THINK we see signs, which causes stress which could create signs?

Or may she be pregnant?