My cat got spayed 6 days ago and today I noticed that she has a lump at her incision site. When she is laying down or relaxed it is not there but when I pick her up and she get's stretched out a bit it turns into a big, hard lump. I tried to get photos but I couldn't because I was alone and I have to hold her with two hands to see the lump. Is this something I should be worried about or is it normal? None of my other cats ever had a lump like this when they got spayed.