You are definitely not overweight. You are probably just wearing your jeans too tight. What size are you buying? I am just about a half inch taller than you and I would kill to be 135 pounds again. That was a very good wieght for me. I weigh about 155-160 now. You probably just need to make better choices when you go shopping.
According the the AMA, your Body Mass Index is 22, which is exactly in the middle of the "normal range" . Your ideal weight should range from 113-148 pounds. Your description of the "ugly muffin" makes me laugh. i have never heard it called that, but I would say that describes a lot of women, myself included. Maybe some toning exercises would help, but I have been doing it for years, and nothing seems to help mine. Seems as though it is a function of having carried two children and getting really stretched out. It's like a left-over skin flap from liposuction. I have decided that in order to love myself, I have to love it too, as disgusting as mine appears to be. So, nope, you are not overweight! Congratulations!