Progesterone...

I went to my doctor last Monday to check for ovulation. I found out yesterday that I am pregnant. She told me to come and in last night and she drew my blood again. She said that I was a lil low to have gotten pregnant. Would that be normal for like a week after ovulation or no ?? And would 5 weeks be to late to start progesterone?? In already 4w4d and I have to wait for blood to come back and I just don't want anything to happen before I get it if I need it.