Uhhhh help?!

Im 28dpo and exactly 2 weeks late for my period. I've been testing since 1 week late to now (2 weeks) and I'm only now seeing something? Is this definitely a positive? And another random question is, why am I only showing a positive at 2 weeks late and in the middle of the day instead of from day 1 onwards in the morning? I used a clear blue from the start and now I'm using a cheap box of 20 from Amazon (didn't even know they were a thing)! Is it possible I ovulated late? Me and my partner tend not to do the deed during my fertile week so this is a bit of a shock 😅