Weird Sour Odor in my Bedroom?

Hey, about a month ago I noticed a weird sour smell in my bedroom something like rotten berries or such, I've noticed this smell outside before and other places around my block (just the other night I noticed it near this one house) But for some reason it's all inside just my one bedroom, but outside the bedroom window there's no smell at all, I actually narrowed it down to the bedroom window though cleaned the hole thing but the smell was still there, in the side corner of the window it was really strong, but there were also some tiny holes in the wall there so it was either the corner of that window or the holes doing it, but I patched the holes with drywall and sprinkled baking soda over that area, and window smells been gone since, (2 weeks later) I was just in my room 5 hours ago, and it smelt fine, I just got my shower all ready for bed and BAM that smells all in my room again, I tried to smell around the area it was before but I think it's coming from somewhere else now, I would have to locate it again by airing out the room etc but damn I'm tired as hell, think I'll sleep in the living room tonight. Any ideas though?