this is normal and when you sit down sometimes it feels like your sitting on babys head! lol, just lower yourself down slowly :) also you may get pains that feel like electric shocks, this is from the baby moving its head on your pelvic floor muscles which is also normal, not a nice feeling, but normal :)
most likely means your baby has dropped.. mine dropped around 32 weeks and i gave birth the day before my due date.. it can help with dilation as there is more pressure on the cervix.. i dilated to 3 cm 2 weeks before lbor.. if you start haing regular contractions -- more than 4 in an hour you will want to get seen as you are still preterm