Morning after pill pregnancy???

Hello!

So a week ago I had unprotected sex (during ovulation) and took the morning after pill within 12 hours after this.

2 days ago I started my period 10 days early, which I know can happen after taking the pill. However I’ve now stopped bleeding, the blood was very dark like old blood, and relatively clotted.

I know I won’t be able to take an accurate test yet, but I just wanted to know if anyone has experienced similar issues, my boobs are ridiculously tender, and the only time I can think back to when they were this sore was with my 1st pregnancy. I’m aware that my tender breasts could be a side affect of the morning after pill, I guess I’m just getting slightly concerned that it wasn’t successful.