Freak out!!!

Husband and I did the dirty deed last night lol! Not because we were trying, hoping we already are pregnant 🤞, but just doing the bd for fun. Well I went to the restroom to pee but when I wiped to my surprise I was lightly bleeding. For a moment I thought AF came because she is due the 5th but it stopped. Took a PT test this morning and negative. So I’m guessing maybe it was a start to AF but I’ve never had this happen before. Insight on this would be greatly appreciated