Stabbing pain in back

Br

I am 37 weeks (tomorrow) and ever since last night, I’ve been getting these random, stabbing pains in my back side on the right, like someone has punched me or stabbed me, it’s slightly painful, and catches me off guard to the point that I’ll jump when it happens, and I’ll cramp a little afterwards. Not sure what this is, and if anyone else may be experiencing the same thing?