Constipation remedies ?

I’m 18 weeks pregnant and this last week I’ve been horribly constipated. TMI sorry. I asked my OB and they recommended a list of foods high in fiber and told me miralax was okay to take. Well I’ve tried the foods and even taken miralax 3 times in the last 3 days and still nothing. I feel so uncomfortable and I can’t remember the last time I went to the bathroom. Please help. Any pregnancy safe remedies for constipation?