I had an irregular period before I even started the pill...but when I was on the pill it was like clockwork. Now that I'm off, I have been going between 42-56 days! My doctor said that for the first 6 months of going off the pill, your period can be messed up (come early or late), she said under 40 days is fine for that time. I have been off the pill now for a little longer than that, and my period cycles are over 40 days. There's a chance I'm not ovulating I guess...or it could just be stress (we just closed on our first house and moved and all).
Anyways, does that answer your question? I think around 35 days is fine. Are you concerned about it? You could always just call your doctor and ask.