Had been abstinent for 5 years. recently started having intercourse again and my vagina is sore. is this normal after a long period of abstinence. sex isn't painful the whole time but is a bit sensitive at the begging?

It is likely that you are overdoing it. After that long of a period of time, it would be advisable to try to ease into sexual activity again. If you have persistent pain or problems, see your gynecologist. Good luck.

You may have insufficient natural lubrication. Try using a liberal amount of a water-based lubricant like KY jelly in your vagina. Get HPV vaccine. Wish you good health! Safe sex: https://www.hopkinsmedicine.org/health/wellness-and-prevention/safer-sex-guidelines