Labor contractions: Clarification on what to feel

Hi momshies, pwede mag-ask? Ung contractions ba na mafifeel during labor is paano madedetermine if true labor na? Sabi maninigas daw tiyan, what if manigas just because si baby ung nakaumbok? 38weeks and 3 days here. Masakit na puson and likod ko. Thank you in advance mga momshies 🙏 #FTM