It is extremely uncommon to have a seroma post Tickle Lipo. Honestly, having performed literally thousands of Tickle procedures, I have never seen one. When I did VASER, it would see it on occasion. With that said, a seroma ( which is a fluid collection of normal body fluid called serous fluid) is not impossible. The fact that you say it is hard makes it less likely unless the overlying skin is taut from excess fluid. Usually seromas are soft and somewhat mushy. It wouldn't hurt to attempt to drain it first, but most likely it is not fluid and a persistent change to the tissue secondary to healing process called proliferative healing. In addition, there may just be some asymmetry of fat removal in this area as compared to your left thigh. In that case, a touch up of your Tickle procedure would be in order. Last resort would be a steroid injection using Kenalog.