I have a question, bear with me I don't know how to explain my pain very well lol. but I'm 32 weeks…

I have a question, bear with me I don't know how to explain my pain very well lol. but I'm 32 weeks pregnant and tonight I got this awful pain on the upper left side of my stomach/abdomen, and it tightened up like hard as a rock. it took my breathe away and it stopped me in my tracks. I'm assuming it was a real contraction instead of a braxton hick bc of the pain but not really sure. it only happened once. but every since then my lower half (vagina,bladder area) is really achy and my lower back hurts. and since it happened I just feel exhausted. and now everytime the baby moves tonight it's not painful but it's uncomfortable. does this sound like normal pregnancy pain? or signs of early labor? or something else? I have a doctor's appt tomorrow but I want some answers now lol. please help!?!