So confused. Period is out of wack!

Brandy • Married 1-11-14 and we have a wonderful 3yr old due with #2 in January 2016
So my periods over the last few months have been 33,32,31,28 days apart seeming to get closer together usually lasting 4-5 days. My last period was Feb 13th then on Feb 27th I bled for 3 days like it was a period but that was only 14 days after my last real period so I chalked it up to ovulation bleeding, well if I count my last period as Feb 13th then I am now on cycle day 37 with no sign of a period. So if it were you would you count the mid cycle bleeding as another period or not? I took a pregnancy test a couple days ago and it was negative.