Sayang, please go to the hospital or call your doctor/midwife sekarang jugak, better safe than sorry, especially since you're a first-time mum and the tightening + pain + pressure is happening together like this. Don't worry, it's super common to feel unsure during pregnancy (a few of us first-timers were the same!), but the healthcare team needs to check you properly to make sure baby and you are doing okay, that's what they're there for. Could be Braxton Hicks or it could be something else, and only a proper check can tell. Go now, yeah? Keep me posted!