Aw, that sounds really uncomfortable! At 9 weeks, a lot of weird aches and pains happen because of hormones and your body shifting, so one-sided butt cheek pain is not super unusual, a few of us had random pains sa different areas during early pregnancy. That said, if it's sharp, getting worse, or you're worried it's something else, best to mention it sa OB mo next visit or call them now lang para peace of mind, especially if it's accompanied by other symptoms. Hang in there, mama, pregnancy is such a rollercoaster of strange sensations!