Tongue tied infant and feeding?

My 9 week old is feeding but it is still not as comfortable as I think it should be. I occasionally get a clear blister on my nipple but then it goes away after a few days (from friction or too much suction?) feeding isn't too bad during the day but by evening it gets more painful. I was wondering how to tell if tongue tied is affecting feeding/latch. I asked his Ped this morning at his visit if he is tongue tied and he said its too early to tell for sure. My son is gaining weight well (25th to 40th% now) but I was just looking for any tips to make feeding more comfortable. I know I can see a lactation consultant- I am a OB RN and work with them- and I know about tongue clipping. I was just looking for something I could use right now if anyone has experienced this.