Plan B taken in March No Period

Ok I had my last period last March in the 10th I took a plan B a week later and got another Prriod on March 23,2017. I was spotting Pink for like 7 days in April, very light didn't fill a tampon and I had it in all day 😔. It's now June 1st and I still don't have a period😩
I feel extremely bloated as of today and my stomach is poking out a little now. I've been to the doctor and hospital and both places say negative and I've also been doing home test. All negative.
I've been very stressed out though to say the least. So that could be why but I haven't been stressed out for that long and it's been almost 3 months since I've had a period. If I am I happy because my son is 5 and want him to have a sibling. 
Could i be stressed out or could I be pregnant or could it be because or the plan B?