Can’t tell if I’m having contractions

So tonight what started as mild cramping in my lower back has turned into what I think might be contractions? It’s 3:30 am I just want to sleep and I don’t know what to do I’m only 36 weeks and 3 days ): I don’t want to wake my hubby up and go to the hospital for no reason): it basically feels like period cramps from hell but mostly in my lower back .