Painful swollen muscles in my arms and legs after period, what could it be?

Hello everyone, I need your help, I haven't had any success at the doctor so far and Google hasn't come up with anything either. I have problems that typically occur a few days after the end of my period. But not every month, sometimes only slightly.

This is what happens: My forearms and thighs feel extremely thick and swollen, so that movements are strenuous and often painful. However, the swelling is more in the muscles, i.e. where the forearm and thigh are thickest and not at the joint. It also feels super hard there. Of course, all doctors immediately think of edema (water retention), but according to the vascular specialist, it is definitely not edema.

When I stand or walk for long periods, my legs hurt really badly right up to my lower back and the muscles cramp up so that I have to sit down. But I can do short periods of exercise such as squats or press-ups without pain if it's not too long. So its not about the intensity of the movement, but how often I repeat it.

I'm a bit older, so it could also be related to perimenopause, but it doesn't seem to be one of the typical complaints and my cycle is quite regular. My gynecologist couldn't say anything about it either, except that I could try hormonal contraceptives and then see if it goes away.

But before I try that, I wanted to ask if any of you have ever had similar problems. If yes, what helped?