Is my guinea pig pregnant?

Well she was accidently housed with a male because apperiantly petstores can sex guinea pigs according to gender , well she has lumps on her side and you can see them clearly when she walks because her body streches out and it looks like she ate something HUGE and she has just a huge stomache , and she drinks and eats A LOT. Also how far along is she probably? I thought I saw the "babies" kicking but it wasn't very big kick it was like soft kind of like a heartbeat. Thanks!