Did you get pregnant two days before ovulation?

My OH has gone back to the army, we BD'd Sunday and that was two days before ovulation was due. I felt very nauseou and back ache the next day so hoping ovulation happened then? He won't be back for 6 months so ttc is so hard 😪 hoping this is it! He's rarely able to come in my fertile window, normally at the end or start of my cycle so this was a prime opportunity! What's my chances?!