37 week contractions

FTM here. Last Friday I had my first definitive contraction. I’ve experienced things that I thought may be Braxton Hicks but I truly had no idea if they were or not. Friday’s contraction was strong and lasted about 40 seconds. Nothing else happened until Saturday when I got another strong contraction that lasted about a minute. Then last night I experienced another (stronger again) that lasted about a minute. Is it normal that they are so spread it?