My cat claws me all the time and draws blood

I've been staying with my mom over the summer with my boyfriend. I am currently almost 7 months pregnant and she has a cat that claws me all the time. I lived here before when she had this cat but she was only a kitten so she never clawed me then... every time I walk past her her claws go into my skin and I end up bleeding every time. I do yell really loud because I mean... It hurts. I have multiple scratches all over me and marks. She doesn't claw my boyfriend or my 7 yr old sister, but she does my 14 year old sister. Does anybody know why she would be doing this? It's beginning to frustrate me to say the least. Cat scratches during pregnancy and in general are dangerous. It makes me mad because my mom is out of town right now and I'm holding the house together. I take care of these stupid cats just to be scratched up and bleeding it's really beginning to piss me off. If there is another group that this should be in, please comment. I would think that maybe it's because she doesn't like me here but she does it to my sister to so I'm just not sure why. My mom wanted her claws removed along with the other cat because they scratch up furniture. I don't think it's very humane so I convinced her otherwise. I wish these cats knew i actually cared about their fat asses!! I feed them and change their litter and love them as much as possible.