38 mom of 4 ... pregnant with #5

Hi all, I’m 38 will be 39 in September. Mom of 4 (20,14,8,&3) I also lost a child in 02, making this pregnancy my 6. My husband and I have very opposite work schedules making it very difficult to have “us” time. My last period was 2/2, which wasn’t much “us” time in February, but we did spend some time 3/8 and according to Flo/Glow and a couple other period trackers I was 11 days late. We joked about it because I have very irregular periods, and my age so naaaaa not possible. Well while shopping the dollar tree I decided to buy a test.... but could we have gotten pregnant 3/8 that was the ONLY time we had sex, other then being rabbits the whole month of January.

Again my last menstrual was 2/2 and it was my normal 5 days. He’s excited yet I’m scared out of my mind.... I’m 38yrs old. Any thoughts ? What should I expect so late in age ?