Help again?

I have been taking the pill for a couple of months and I have been having two periods a pack. One on the second row of pills and then the sugar pills. However, this pack, I didn’t get my second row period. I did have a period on the first week of April and I have been insanely stressed and worked up (boyfriend broke up with me but we had sex the day prior and finals coming up) so could this be the cause of it? I took a pregnancy test and it said not pregnant but I know there can be false negatives...

update: I have taken two more tests since and they still say not pregnant so guess It must be stress or another reason