See if eating a banana a day helps. Could be low potassium in your diet.
It might be a potassium issue. Try eating a banana a day to see if it helps.
Magnesium did wonders for me in my last two pregnancies. I used Calm which is a powder you add to water. I also have magnesium oil I rub on my legs. Works great for restless leg syndrome and tight muscles.
Make sure you are getting plenty of water throughout the day. I notice I tend to get leg cramps when I may be slightly dehydrated. Also, do a few leg stretches before going to bed.