Why are my cycles so messed up?

So I'm 50 y/o and going thru peri. I'm on progesterone and estrogen to help control the awful symptoms (namely anxiety). I know that irregular cycles are a normal part of peri but I have had two instances recently where my periods are only 15 or 16 days apart. Is this normal? Also I have a lot of cramps and blood clots with this current period which hasn't happened since I was a teenager. I will be seeing my gyno in a few weeks but I was wondering if anyone else can relate to my issues.