The pain you are experiencing could be of neural origin; vascular pains do not disappear, yet you may have to rule out the possibility of a vascular pain in your neck as it is throbbing in nature. The possibility of an embolus after the previous caesarean section
depends on the post-operative outcome at that stage and the duration after surgery. The pain is most likely due to this pregnancy
and you may get further advice from your doctor. Wish you safe motherhood.