Headaches and Constipation...... help!!!

Hello knowledgeable ladies.... I need some insights.

I’m 15 weeks pregnant today with (my second) baby girl!!!

The nausea is easing.......But my head is pounding most days. It’s so so bad.

I had my eyes tested and blood pressure checked and all is well. But my head 🤯.

So I saw on a thread on here about the Magnesium drink Calm and bought it out of desperation. Now I daren’t

try it incase it is a risk to the baby.

I’m in the UK and I’ve never heard of it.

Can any of you wonderful USA ladies give me some advice? Will it help my constipation too?

How much should I take?

Thankyou so much xxxxxxxxxxxx