Actually he definitely looks malnourished in the picture. What pellet brand are you feeding?
Freeze-dried bloodworms are really bad and can cause constipation, they're okay for like once a week but no more than that. Frozen Bloodworms you can do twice a week though. I use New Life Spectrum Betta Pellets and Omega One Betta Buffet Pellets, both are the highest quality at the moment and really not expensive (4 dollars something and 3 dollars something respectively). I feed both to get a nice variety and usually feed the boy's anywhere from 5-8 and sometimes up to 10 pellets if they look like they need it.
When I feed my fish I tend to go by how big their stomach get's, once I see that they're starting to look a little stuffed, I stop feeding which is generally around 6 NLS pellets for most of my boy's. My older boy's get a bit less and my constipated boy (birth defect) get's only about 4 a day. So I think you really should bump up feedings for sure.
Since you don't live in a very warm area, or either that your A/C is on....you really should get a heater. 73 is too low, also Beneficial Bacteria don't like the lower temps much, they'll survive but they just won't like it much.
So, do you have a filter and is your tank cycled?