Battery keeps dying

I have a brand new battery (bought in feb this yr for this same problem that recently started happening again.) I'll try to start my car and it's completely dead (usually in the morning or after sitting for 12+hrs). I get it jump started and it runs fine. Before I replaced the battery it would last without another jump for like two days. But I had to get it jump started like every other day. The car runs great otherwise! I kept getting the battery tested and it was fine, alternator fine too, so I just bought a new battery and I thought the problem was solved. I had no problems with it from February until July. In July I flew to NY for a week and my car say parked in the parking lot for a week. When I tried starting it it was dead. Repeat of original problem. After getting it jump started and driving to work for the day (charging it back up) I had no issues for the next 3 wks. I figured since it was a new battery and again it tested fine that maybe I had left my lights on or something. But then this morning, after just driving for a short trip to the grocery store 1 mile away over the weekend, it would not start. I had to have it jump started AGAIN. Obviously something else has to be draining the battery so my question is: what could be causing this? Any help is greatly appreciated. I am 8 months pregnant and I do t know where to take my car where I won't get ripped off. I know most places charge an arm and a leg just to test it and I also can't afford to be without my car for very long. Like I said, the car runs great once it starts and I really like the car. Please help.