should i b concerned?

my period before I had my baby (1st baby) was always very very heavy with really bad cramps and would last 1 week now that I had a baby I notice that I will have sharp pain I wanna say on my right ovary here n there I'll spot like 3 days and then I'll start my period and when I am on my period it'll b heavy but no cramps or pain(which is great on that part lol) anyways this past month I started towards the end of the month and my period kept going till the beginning of July as well for the first 2 days I wanna say .. now I haven't started since I was expecting my period this last week of this month and nope no signs of period I took a pregnancy test and its negative I was wondering is this normal? also the pain I feel ? I'm just so confused at all this ... can I miss my period n not b pregnant? thanks in advanced!