glow vs fertility friend

Mariah

help! glow has my ovulation at CD18 which gives me only a 9-10 LP for a 27-28 days cycle and I dont think thats right... its not accounting for my paying attention to CM. well having the option to override in fertility friend, i get to account for CM, CP and temp. (um, that unaccounted for temp was date night so even if.......) what do you think? also, AF expected fri or sat, too early to test?