missed period

So I've been on birth control pills for 10 years now and decided to come off in June 2016. I had a normal period but after my period I was constantly spotting. Like now stop. So I decided to get back on the pill to help with my spotting because I was tired of spotting all the time. Then in January 2017 my husband and I decided I should come off the pill. And I had a full period in January but February and march I had very light spotting and in May I didn't have a period at all. But take pregnancy test and they all been negative. Anybody else have this problem