Cramps 1 week before AF

Madison • Vas reversal 6/2013. IVF 10/2015. FET 12/1/2015. First ever Positive Pregnancy test 12/6/2015!! Baby due August 2016! :)
Does anyone get this? I think I have it with every cycle. Cramps are very mild and only last a few minutes here and there. If you get this, have you been tested or diagnosed with anything? Thought cramps weren't suppose to start at all until CD 1 or a day before. I'm 6 DPO