Can a positive show up later in cycle?

[HanaBubby]

Hi everyone, so I'm currently on day 29 of my cycle. (Average 27). I normally get a dull ache the day before or of my period but this time I only got a slight twinge on my left side. A few hours later followed by slight brown discharge when I wiped. I assumed it was AF on the way but still no show so now I'm curious was it implantation?
Iv been taking regular tests as I've had a few suspected 'evaporation lines' get my hopes up. So far a week ago I got 2x negative Clear Blue tests, followed by positives showing up 30+ mins after testing. Switched to First Response and they have come back negative.
Any idea?

Hi OP. If that brown blood was linked to implementation then I think it can take a couple of days to show as a positive. Not trying to get your hopes up or anything but I have read way more than I am prepared to admit about this and that's what a lot of people report.

Try again in a few days, good luck!!

Yeah I'm unsure as I never had this with my first. With him I just took a test in the day of suspected period and it was positive. I've had more of the brown discharge again, with some slight bright pink in small bits throughout today. (sorry for the TMI!) It's no where near enough to even be considered a period so going to bed tonight without pad or anything. If it doesn't come in full swing by tomorrow which it should definitely of done by now, I'll book to get some bloods done.
Anyone else got any input with have implantation bleeding before?