Trying to conceive

My last period start date was Aug 30th end it sept 3 I've had been using track app to keep up with my period and it says the next date I'm suppose to start my period is Oct 25th if I'm not pregnant but tells me my period is also late so I'm confused and today what seems like my period was a red and orange color then all day today it stop it hasn't came back two weeks ago took pregnancy test said negative now I'm waiting to see if my period will start the 25th or come tomorrow since it kinda seem like spotting but not sure please help if you ever been in this position