you really need to just communicate more with her. we can’t tell you exactly what’s going on in her head. she could mean that it’s a mixture of pleasure and pain, or she may be into pain either in a masochistic way or a self harm way. you should really just work with her to figure out the best ways for you to get each other off. she could just be adjusting to things and might need longer foreplay. make sure she’s wet and relaxed before going to reduce any friction and muscle tightness