Ohhh sakit celah paha tu memang common dalam trimester ketiga sebab baby grows and hormones loosen your ligaments, but kali ni you should still check with your doctor to make sure it's not something else like nerve pressure or infection. A few of my mum friends had the same thing dekat 36 weeks and it went away after delivery, tapi better safe than sorry lah kan, especially since you're first-time mom, just WhatsApp your gynae or clinician to describe the pain, buat sure aja!