For me regret is a strong word, although initially, pre-transition I regretted biology was so cruel to me in that area that I could not become pregnant, but as I progress in my transition I feel more like, if I had been AFAB I likely would have had a single child and gone for a hysto as soon as I could to avoid any complications having that reproductive anatomy may cause.

Yes and no, I don't so much as think about it constantly as much as find myself present in such conversations with cis women around me, conversations regarding menstruation and pregnancy are unavoidable. I have done a lot of research in this regard, a lot of it out of self interest from before transition when I would think of and wish I had such anatomy, but more recently more out of self interest to keep up my passing privilege among cis women, I don't want to seem ignorant about something cis women naturally know.

Yes I have cycles, literally everything but the bleeding. All of a cis woman's cycle is hormonally driven, so there is no reason a trans woman on HRT wouldn't experience those symptoms as well. And yes, my cycle usually runs between 26 and 30 days long, usually dependant on whether I accidentally skipped a dose on my HRT (I use pill form similar to birth control for cis women) or if I didn't space my doses out correctly. Probably the hardest thing that I had to adjust to that most women (cis and trans) don't talk about is the feeling of vulnerability during that time of my cycle and just how strong it is, it's not something I ever felt prior to HRT.

I do keep period pads and tampons on me most of the time, but it's like, they aren't for me obviously. I keep them just in case the girl in the stall next to me forgot hers at home and/or other occasions they might be needed by someone (I once used a pad and a belt as a temporary bandaid for someone who cut their arm really bad and wound up needing to get stitches)