so I created this account with my sons girlfriend. she isnt sure when her last period so we did process of elimination to narrow down the closest possible date of her cycle.thats how we came up with her dates. July 15 ago we went to family dollar and bought a 4 dollar test. it came up positive but the lines were supposed to be horizontal...the control was but the pregnant spot was vertical. so we waited 4 days and bought a 3 pack of clear blue and it showed a very extremely faint line next morning took another and she did have 3 days of spotting about 2 weeks ago. she has all the symptoms of pregnancy. I dont wanna waste the last test...but i am wondering since still no period

it's been at least a month... how long do y'all think i should wait to have her retest ?it been 13 days since test shown.