Anyone experience changes in your cycle AFTER you've started TTC?

We just started trying for our 1st the end of November. Last month I kinda spotted a little when I was suppose to start my period then stopped and then actually started my period a week later. I kinda figured it was because of vacation and all the crap I ate and booze I drank. This month I'm not suppose to start until next week. But this morning I'm spotting again. Not a lot, just on the toilet paper and it’s brown. I'm 30 and started taking birth control at 17, but I've been off it for over a year. My periods have always been very consistent unless I intentionally skipped it, which I didn't ever do often. In the year I’ve been off BC I’ve never had any cycle issues. I’ve always been within a day of when I’m supposed to start.