Weight gain at 20 weeks

Gardenia

I went up until about week 16-17 without gaining a pound. Now between week week 18 and today (20 weeks exactly) I’ve gained 4 lbs! I know they say 1-1.5 pounds per week so I’m actually over that recommendation. Overall I’m up about 8 pounds from my normal weight which was 115 (I’m 5’7”). Has anyone else had big weight gain all of a sudden for no reason? I was a little out of control with sweets and nachos lately but I’ve been trying to get that under control. I don’t want to be neurotic about my weight but at the same time I want to stay healthy and not gain “too much”…still have 20 weeks left of pregnancy!!