Hello! Congrats on your baby
As your midwife said, a lot of women don't find out until months later that they are pregnant. I had my son when I was 20 and because I took my birth control for sometimes months before I let myself have a menstrual cycle, I didn't realize I was pregnant until after my third month.
I wasn't a heavy daily drinker back then but I did binge party seeing as how I was young and I'm a party college.
I immediately stopped everything after I found out of course. I gave birth to a beautiful, healthy boy.
Don't stress about what did happen although make absolutely sure not to do it again. The guilt will only be magnified each time. Please, if you're concerned, talk to a doctor or get some support