any one who knows about cycle tracking

So I got a pregnancy test at the dr. Last Friday it came back negative that was cycle day 29/30 now it's a week later I'm on cylcle day 39/40 
(My cycles are usually 32 days, and a plan b last month started a new period)  I wasn't concerned about pregnancy at all before because of the test that was done Friday now I'm just a wee bit concerned now that I'm on potetially day 40 of my cycle with no signs but tender enlarged breast