Trying for baby #1

My boyfriend & and I are trying for baby #1. I’ve seen a doctor at Planned Parenthood & my body is completely normal and healthy. He’s seen his regular doctor and he’s healthy as well. He’s ejaculated in me numerous occasions, but I’ve yet to be expecting. I was on my fertile window this week & he’s ejaculated inside of me, is it possible for our baby #1? If so, how long am I to wait before taking an at home pregnancy test? Also***Does anyone know if Pre-Seed works?