I was trying to avoid charting because I didn't want the stress of ok I'm supposed to O'ing so we have to BD. It kind of ruins the mood knowing it's a have to thing, if you understand. But I guess I need to practice my charting the next couple of months while my fiance is gone down south to the police academy, that way I will know what I'm doing by the time he gets back. lol
In all honesty, I find not knowing what my body is doing to be a lot more stressful than timing sex. If you chart, you avoid this kind of "should I test/not?" and "am I late/not?" confusion.
It could be that your body is regulating from the birth control. Sometimes things seem normal at first and then they go sideways. Sometimes it's the other way around. I stopped BCPs in July as well and it took about 5 months to regulate. If I wasn't charting, I'd have gone crazy by now. Cycles went from 61 days, 44 days, 37 days, and now 35. You range doesn't seem too crazy too me! But either way, charting will give you insight into what your body is doing.