Longer than normal cycle

Okay ladies, I need some help. I have always had VERY regular periods. 28 days exactly, maybe a day early, but NEVER late unless I was pregnant (I've had 3 miscarriages and 1 child). What have your experiences been with an extra long menstraul cycle? Like last month I didn't start until Day 31, and I'm on Day 31 this month and really can't tell if I'm going to start or if I'm pregnant. I just took a bad test. Didn't aim right I guess. Any help would be so appreciated...