Cramps all the time??

RUX • TTC for second baby 😊😍

This is my first cycle with letrozole. Through out the cycle am having cramps like AF is coming. Today its CD21 . I had worst cramps on CD11 and CD12 . Did my ultrasound on CD13 and i was not ovulating!! Then my OB said to try on my own.. Again had my worst cramp on CD 16 and CD17. This is making me so so confused.. has anyone experienced the similar? I also got huge EWCM on CD 12 and CD 18 . Am not testing for ovulation!! What does this mean?