Look them up on webmd for detailed description. Make sire you have your sic check it out when you go, and maybe see if you can go in early for this if it is really uncomfortable. They are common in general with constipation and with pregnancy for that and other reasons. Tucks and Preparation H will help with the discomfort. Webmd has other suggestions as well. Good luck!
Its commen to get them during pregnancy. Exspecially after you give birth. Try getting medicated tucks wipes. They really help.