bed bugs and pregnancy

I am six months pregnant and just found out we have bed bugs. We live in an apartment complex. They sprayed about a week ago but we forgot they were doing it so we had the door locked and slept through it so they never made it to our apartment. I am freaking out. I am unemployed and going to college full time. My husband is the only one with a job. There's no way we can afford to get a new mattress. The treatments are $300 and that's out of our price range too. I don't know what to do. My dog was just diagnosed with breast cancer so all of our money has gone to treating her. We literally have nothing now. We lived in a really run down apartment complex about three years ago and got bed bugs. We were never able to get rid of them so we had to throw out all of our furniture and move. We can't do that now. I am absolutely freaking out. Please, someone give me advise.