Advice! Opinions! I

So I posted the other day about my situation, I'm currently on cycle day 65, AF has not showed herself. My last period was 6/17/17...my pregnancy test are so invalid...in the timeframe of taking them its supposed to be only 3 minutes...never had a problem with the "first signal" test before up until recently I will look at them hours later and there will be a faint line, but not really evap because they all have color, but because they show up hours later I discard them in the trash. I've researched everything, and its driving me insane. The only thing throwing me off is, I missed my period. I have 12 days left this month to get my period, and if AF doesn't show I'm going to buy a digital test, instead of the 88¢ one. Also how do blood test work? Are they accurate? Is it possible to not have a high enough level of hcg yet? Maybe I'm just not pregnant...my breast are so sore, and I just hope it's not PMS related. Anyone out there going through this???