FLEAS!!!!! Help!!!!

I am hoping someone can help me. I have fleas in my brand new apartment. The apartment was clean and had new carpets put down before we moved in. I live in a small apartment building on the beach. Tenants are NOT allowed to have pets.....we don't have pets....and no pets have been in my house.

We live on the water in Los Angeles so there isn't grass- and people don't have yards. I've been researching sand fleas but they look much different than regular fleas. I also don't believe we have any mice or rats in the area or in our home. Neither could get into my second story bedroom (and I always keep my door shut during the day while I'm at work). We also don't leave food out and haven't had any issues with food in our pantry.

I had fleas at my previous apartment in October 2012. I believed it was from the previous tenant who had a black lab. I must have bug bombed my house 3-4 times, used the Boric to sprinkle into the carpet, I used the solution to suck up into my vacuum so the fleas couldn't survive. It took me a solid month to get rid of them.

I found 1 flea last night and 1 the night before. I don't want to "bug bomb" again because I don't think it's very effective. Does anyone know where these fleas could be coming from?? Could they have survived from my October incident? Does anyone have any recommendations how to get rid of them? Please help me- I can't deal with this again.