Partner's Cycle

Okay so here is the odd question I have but have not been able to bring myself to ask my OB/GYN, even though she knows I am in a same sex relationship and my DW has been to every baby appointment (even the one where she was discharged an hour prior the day after gallbladder surgery and was in tears from the pain) and that we conceived with an in home kit and donor friend...

 Has anyone else found that their partner's cycle has changed since pregnancy?  I only ask because I was always the odd ball every 7-8 weeker with PCOS and that was on Metformin (getting preggo without medical intervention was a blessing as we could not afford it) while she was a you can set your watch by it 25th of the month done in five to six days max (she was going to try if our last attempt had been unsuccessful, luckily for my butch wife baby decided November was the charmed month).  Now that we are expecting she is ALL over the map...and the pregnancy is the only thing that has changed in our lives in the last year.  It is actually coming about every 3 weeks now but is shorter.  I just wondered if annyone else had this happen or if it is something else...