Spotting when my period was due

Ok so my last period was Sept 4th. And I was period was due Tuesday Oct 2nd I only spotted a little then nothing. The 3rd and 4th I had nothing at all ,then Friday Oct 5th I noticed in the afternoon I had spotted a little again and then it stopped. And here it is Saturday Oct 6th the last day of what was spose to be my period and still nothing . Wednesday Oct 3rd I went to emergency they did a pee pregnancy test which came out negitive. I toke a test yesterday evening and then early this morining toke another one . Both I could swear they looked positive but when the tests dried I wasn't so sure they looked positive cause it was hard to tell this morining I have emergency call me and told me that a bladder infection show up in the test I did at emergency. So I have been very stressed out as to why I only had spotting when my period was due and why I haven't got a strong positive pregnancy test yet . I never spot on my period ,only time was back when I was pregnant with my 2 daughters. I do have a doctors appointment for thw 9th of oct .Anyone have any ideas of what