Periods after BC

Melanie
I'm looking for a little help/insight.  I've been on birth control (the pill) for about 15 years.  I got off of it in April because we are TTC.  
From what I remember as a teenager before I got on BC, my periods were extremely painful and lasted 6-7 days.  While on BC, my periods always lasted 5-6 days, pretty heavy flow, dark blood with clots, with a good bit of cramping.  
My 2 periods I've had since getting off BC have only lasted 2.5 - 3 days, one heavy flow day with a lighter red than I'm used to (not bright red but definitely not as dark as when I was on BC), no clotting at all, and not really any cramping.  
I did my first OPK this last cycle and I had about 7 high fertility days before I got to a peak day.  I've taken 2 pregnancy tests and both were negative.
Is such a light period with no clotting normal after getting off BC?  My first thought was wondering if I'm actually ovulating but wanted to get a few opinions before scheduling a doctor's appt.  Thank you!