Being bitten almost every night, but by what? (pic)

http://i44.tinypic.com/15d780h.jpg

Im wanting to say mosquitos since i saw ONE, ONCE. But the bites are so big, they're unlike any mosquito bite ive had before. I havent seen any other insects or spiders in my house... Also the house is sealed up tight, nothing can get in. (just a little apartment with one door anyway).

Its only happening at night, and these bites happened when it got too hot in the house and i didnt cover up with covers. Normally when i have covers on me only my ankles/arms that stick out get bitten. So im more inclined to say its something that cant get under the covers.

This has been going on for about 6 weeks now, and i live in virginia (meaning its pretty cold here 30-45 degrees farenheit if that makes a difference ruling out the culprits)