Extreme calf pains

So I'm not sure if this is or even could be related to pregnancy but here it is! I am currently 35 weeks and every night in the middle of the night and at random times, if I wake up and stretch my legs I get the most extreme pain I've ever had in my calfs and it takes almost a minute to stop. This has been going on for about 2 weeks now and just not sure what it is from or if anyone else has had that.