I have 2 female hamster and they get in fights a lot and resently I've looked at one of them and she has a cut with blood on it(not bleeding anymore) on her back,stomah,and under her tail please help I'm so worried

You need to separate them. Hampsters are solitary animals, and they will more then likely end up killing one another if they are housed together. You should try and take her to the vet, but if you can't maybe wash it out with an epsom salt solution. Do not get your hampster soaked or fully emerge her. Just take a cloth and dip it in the solution and wipe around the area if that's possible. You could probably put some anti bacterial oingntment on it, just lightly cover the area with a q-tip.

Like Aurora said, most hamster are solitary animals. Only a few breeds can live together, but the majority of those sold in pet stores cannot.

If you don't separate them then they'll likely kill each other eventually.

Why didn't the pet store tell you this? This is a well known fact. I cannot believe they'd sell you two hamsters, and females on top of it.

Get another cage ASAP and house them apart.

Good luck.