body question

so i just recently started having sex again (after one time about 7 months ago). this time it’s with a boy i’m actually interested in and want to have sex with. well this past friday we tried it and everything went pretty smoothly, only a little soreness around my pelvic area and this may sound weird but my butt cheeks hurt the day after, not to the touch but like the muscles inside hurt when i would sit down or put any pressure on them, nothing major though. and last night we tried other things and i woke up with a bruise feeling around my inner thighs. we were going at it almost 30 to 45 minutes. im not used to doing this, i’m practically a virgin (but not really; i’ve had sex two times in the past two years) and he was totally a virgin before friday so it’s not like we’re going hard core or anything. i just wanna know if these things are normal and i’m not internally injured lmao. thx!