My fiancé and I had sex yesterday night. The next morning I used the restroom and saw that I was spotting light pink blood and my period isn't due for another 12 days. Later on that day I experienced headaches and nausea. Could this be early signs of me being pregnant?

No no far to early...

I have the same problem but I took a pregnancy test and it came back Negative. Maybe it was too early to tell. The doctor just told me to wait a few more days and take another test...

I have the same problem. I just got off my period and had intercourse and some pink blood with a little slime. I know that after you get off your period, you start to ovulate again, so that't where the slime comes from.
I've read that dryness can cause spotting after intercourse. For I did feel a little dry inside. I had a baby 8 months ago and I do know my cervix isn't the same. My uterus is tilted. So certain types of positions during intercourse makes me bleed. I tried intercourse with my butt facing my husband ( was laying down) and I got on top that way and I didn't bleed at all. So maybe you women has the same problems. Your uterus can be tilted and that makes your cervix different too. But if you didn't have children , you could be dry even though you may think you're not. Try almond oil to lubricate yourself. It's natural. SO good luck to all.