Should I be concerned my baby hasn’t rolled yet?

She is 4 months and can totally hold up her chest when doing tummy time. But she just hasn’t rolled yet and doesn’t even look super close. I try to help her with it every day but idk what else to do. I brought her to her 4M appt and the dr said to continue doing it 3 times a day but once she starts getting upset to continue for 5-10 mins. I did that the other day but she got so hysterical i couldn’t handle it. She already does good for several mins on her own. I’m a FTM so idk if this is something I should be really concerned about