When is the absolute earliest you can show signs of pregnancy? I had unprotected sex a week ago and my SO finished inside of me. I’m not on birth control but I took plan be right after it happened. I thought I got my period yesterday, however it hasn’t been as heavy and the blood is brown, as if it were old (it feels more like I’m on my last two days rather than my first two), though I did have some cramps on the first day.

Any information would be greatly appreciated.