femafa and late AF?

Ba

this is my first round of femara... im currently 16dpo and AF not here yet... at 12dpo i had little bit of light pink and light brown spotting only when i wiped so i thought AF was coming... but it was gone by the next day (13dpo) i didnt have anything..no spotting...i took a test and got a BFN...in noq 16dpo and still no AF and BFN.....anybody else have this happen? and still got BFP??