Low lying placenta

I'm 33 weeks pregnant. My doctor told me my placenta is 1.8 cm from my cervix. For a vaginal delivery they want it to be 2 cm away for a clear path for the baby to come out. I have another ultrasound in 2 weeks to see if it moves at all. Will I really need a c-section for my placenta being 2 mm away from the 2 cm minimum? Hoping for a vaginal delivery..Does anyone else have experience with this? Sometimes I feel like doctors push for a c-section just to play it safe, but for 2 mm is it really necessary?