I was going to say the same as Natalie....most commonly babies will start labour with their back down your left side.
As they head south they will "swing" as your obs put it anterior. So all good for you.

I totally understand your paranoia though, my second bub had an anterior placenta and I obsessed about his position from the day I found out....and having the placenta in your front makes it that much harder for you (or anyone else) to palpate his position with your hands which is really frustrating!