Joey & Llori room 33a on 08/22/2011

We have lived here 2 years there were no bedbugs our room - aboout 3 months ago they started pulling carpet, etc in the common areas and i started itching like crazy. finally I saw one and it was big i bombed the room with 3 bombs and threw away all my bedding and box spring but after about 3 days they are back, but i cannot see these ones, i can be looking at my hand and all of the sudden it itches and there are welts but i never saw anything bite me, i went to the doctor thinking it was scabi