Hello there! DH and I are just starting TTC which, (fingers crossed!) I hope won't be too long

I am a new SAHM, was active duty military, but decided to get out to spend more time with my crazy but sweet little 15 month old son. I got pregnant very quickly with him...ahem...honey moon baby (ie first few times ever without protection). But we weren't trying then so i'm pretty sure that now that we actually are planning this baby it won't be that quick. That's life right?
I just had a question about cycles. Before having DS my cycle would be normal for a few months then really long, like 40 something days, then would go back to 30ish days. I've been breastfeeding and just started my cycle again in April and it seems to be doing the same thing. Does ovulation usually change with your period length or does it usually stay consistent, as in always 14 days or whatever after your period no matter what your cycle length is? I want to stay somewhat relaxed about this and hopefully avoid testing for ovulation every month. I watch my CM, but I really to point at calendar and say "these days are best!". I guess what i'm asking is if testing and doing my temperature one month would help me figure out my cycle for every month or does it always change a little? Thank you!!
Re: Hello! Intro and question about cycles
TTC 10/2013
RE Help from 10/2014-10/2016 (11 failed IUIs, a corrective surgery, and a donor embryo cycle)
9/2016-transferred two donor embies
BFP 9/29/26 EDD June 11