Late period / stopping pill / need help

Hi guys, so last month (march 8th) I started on a new pill (the day I got my period) I got it for my endo but it was making me extremely hormonal and in pain so I stoped it about 8 days later, in the mean time mynperiod lasted 5 days and stopped then 2/3 days after I stopped the pill I got another period but much lighter, usually what I got when I was on the pill about 6 months before that (I then stopped to see if my endo pains would calm down) I usually get my period on the 8th of each month or that Thursday, but now my period still hasn't come and I'm getting worried, I've had sex but protected and it's super stressful. I've taken tests about 2 weeks ago but came back negative. Did anyone else experience this? I NEED HELP!!