I am currently burning pine in an indoor fireplace. is that ok?

Any wood will cause resins to build up in the chimney. Have it cleaned once per year, in the fall before you start using it. Call a chimney sweep. Pine is not the best wood for heating but it looks nice. If you really want some heat, hedge is a good wood if you can get it where you are. Apple, walnut hackberry, or locust are good too. Make sure you have a good screen or doors on the fireplace. Hedge can thow a lot of sparks.