Not quite sure. I see my doc tomorrow, i have placental insufficiency so blood flow to the baby isnt great which means lack of vitamins and nutrients and oxygen to baby. I get ultrasounds every week for duration to monitor baby and im only 22 weeks! My point is, sometimes we cant control why our bodies do certain things, they just do. I wouldnt worry but pray. Doc says things can turn around which is great! I pray that things work out in your favor and you deliver a happy healthy baby!
I found out i have partial placental previa (placenta is kind of in front of the cervix) at my 20 week anatomy scan as well. I go back at 32 weeks to check again. Only thing my doctor said was its more than possible for it to move up but if not ill just need a csection.
So my placenta was laying low around the same time as yours. I had since then moved up. The only reason you want to worry is if it doesn't move out of the way you will have to have a c section. And they tell you not to have sex most of the time is because they don't want you to rupture you placenta sack. I should move up as you grow out though. So I would lent worry too much it took mine about six weeks to move
Don't worry to much until your 32 week check up I have same thing I'm 29 weeks have ultrasound coming up in 3 weeks so I hope everything goes well for you and me!