positives, then negative?

Last Friday (7/6), I took a pregnancy test (Clinical Gaurd brand from Amazon). It definitely looked positive to me. I dipped my last Wondfo to be sure, & it seemed positive, but could have been an evap line. I don't know when I ovulated, but am sure of the time of sex, lol. Which was 6/24. But I took subsequent tests during other points in the day, negative, but all I had was clinical guard brand. Some looked positive to me, but only squinting or image tweaked. I took An FRER last night ( 7/9) that was stark white, absolutely negative. I'm going to wait till my expected period to retest (should start between 7/15-7/19). My cycles are normally 30-34 days apart. I'm not sure if I'm pregnant, if I got an evap line & false positive (& am just seeing things on other tests), or if I had a chemical pregnancy (which is admittedly what I'm suspecting). The enhanced image is from 7/8. Admittedly, the negatives were not taken from FMU, but I thought FRER was the most accurate, which was definitely 100% negative but only after 3 or 4 hours of holding. Sorry for rambling, just so confused & a bit emotional. Thank you.