There are some women who have gotten pregnant right after having a child so you definitely don’t need to be having sex without either a condom or on some form of birth control if you don’t want to get pregnant
Did you ever get a definitive answer from your doctor?
Oh boy. First, congrats on the baby!! Second, you have your hands full! Third, that's a significant number of positive tests. After all these pregnancies, you know a faint line is a positive test. Lots of women are extra fertile after pregnancy. The world is full of 'Irish twins'. I got pregnant really fast after I had my first son which was a surprise! However, as we know, very early pregnancy is fragile. One in four pregnancies end in miscarriage. We can test so early now and at home so we catch it when in the past, we'd have never known. It's hard to tell for you though as you haven't even gotten your period back yet. I'd say those symptoms are just hormone adjustments if you hadn't gotten those positive tests. At this point, the only thing to do is to visit your doctor and have them tell you. Do you want to be pregnant again? And as far as symptoms, sometimes they can last even past a miscarriage as the hormones get less and less and they do so overlap with what you are going through post partum or if you are nursing, etc. Please let us know what happens, okay?
I would suggest getting another blood test, perhaps next Tuesday if you can get in.