Help please!

Ok so my period is always on time I track it on the app Flo and have been for about two years so it’s always consistent, flow pretty much knows me. Anyways, so I was supposed to have my period on Friday according to Flo but other apps have said Saturday so I wasn’t really worried. It is now Sunday approaching Monday and I haven’t Got my. I’ve never been late in my life so it’s kind of freaking me out a teeny bit and I went to the doctor and they took a urine test and it was negative and I took two pregnancy test and they were negative a week ago I had a lot of discharge it was wet and it was brown spotting when I wiped but then it went away right after can someone tell me what is going on. I have little cramps now and I had abdominal pain early in the morning but still no. I always use a condom with my boyfriend but it was one time I think he put it on backwards maybe because last week it slipped off inside me but he did not ejaculate it may have been a little pre-come on the inside but I think I tested the condom afterwards and it was no holes sorry this is so long...