Wa'alaikumassalam sis! Eh, this is something you really need to check with your doctor at your next checkup or jangan tunggu, if it's happening a lot or you're worried, better go see them sooner okay? At 14 weeks, tummy tightening can be normal (Braxton Hicks and ligament stretching lah), tapi better safe than sorry! A few of us mums have been there, and honestly the doctor can put your mind at ease in like 5 minutes. Go get checked out ya, no harm asking, it's what they're there for. Take care!