Fat or Pregnant????

Lenny the Lawnmower Blenny is either fat or pregnant. Hope it's not some sort of disease. Anyone know what time frame a Blenny goes through gestation? He or She seems to be doing well other than this huge stomach. Eats like a pig, wonders all over the tank,gets along with everyone. The head half is darker than the tail half and that seemed to happen a few weeks ago. He eats dry and frozen shrimp, algae strips, marine chips and chomps on the glass and live rock. Anyone have any ideas as to what is going on? Should I change his name to Porky or if he is a she Whinney cause she eats like a Ihorse. I have had this Blenny since before Thanksgiving , only one in the tank, so could it have been pregnant before I bought it? Any answers would be appreciated. Happy New Year everyone!!!!!!! 

New name is Gordo. Husband says it means fat in Spanish. Tried to catch him,no luck. My pet store guy did not seem concerned, said to keep an eye on him. He is not constipated. I have seen him poop. He goes to the same spot to relieve himself, kinda like my dog. Have a quarantine tank in my sons room. well did till today got a watchman goby and pistol shrimp pair only other thing in there is one chromis. I took him out of my 180 thought he was the one picking on my other chromis, so out he went to the jail tank.55 gallon bowfront. Just put green bubble tip anemone and black and white clown in the big tank.