Uy, at 13 weeks yan ay normal pa naman, marami sa amin naka-experience ng ganyang Braxton-Hicks-like contractions na dumadating at umaaalis lang, lalo na kapag tired or dehydrated ka, pero since may kasama pang sharp pain sa likod mo, better i-check mo talaga with your OB para peace of mind mo! Basta drink lots of water, rest pag nangyari, at if it gets worse or consistent na talaga, go straight to your doctor na okay?