Low lying placenta 30 weeks+

So my belly measurements keep measuring small because the baby is ALWAYS transverse. Doctor sent me for an ultrasound to make sure all was fine at 28 weeks and baby is measuring perfectly. At my 29 week appointment the doctor said when she reviewed everything, I have a low lying placenta. What the heck, they didn't catch it until now?

Anyway, all the posts I'm reading on here are people catching the low lying placenta in the first trimester and it being gone by 28 weeks... is there ANYONE who they didn't catch it until late? Did it stay or move? Did you need the c-section? I'm starting to freak out and my next ultrasound & appointment aren't for another week and a half. 😯

The doctor didn't mention anything about pelvic restrictions yet or anything, but she did quickly say that they will monitor and if it doesn't move, I'll need a c-section.