I'm four months pregnant and have been slightly constipated for those four months. Sometimes it's better than others but it's usually quite hard to poo. I also have occasional leg and foot cramps.

I take 150mg magnesium bisglycinate twice a day for a total of 300mg; I also reckon I get another 100mg or so at least from my food. Is this now too much? Or still not enough? Is there something else I can try?