Worried about c section?

With my first I had a normal vaginal birth but now with my second the doctor did an ultrasound and said I might have placenta previa so they have to confirm it and if it’s confirmed that they will need to set up a c section I had been having bleeding and one day I was having sex and started bleeding a lot went to hospital and they did an ultrasound they said it was all okay but then a few weeks later like about a month after that I got another ultrasound and my doctor said if it’s confirmed I can’t have a vaginal birth I would bleed a lot.