Need advice

Ashley
So me and my bf have been together for a lil over a year and we have been TTC for about 3 months almost 4 months and we haven't had any luck at all :( but we had intercourse the other night and I started bleeding out of nowhere I know it wasn't the monthly because I had jus went through that like a day or two before this but it's happened to us a few more times and it's only been during intercourse can anyone help me with what it might be??