Bfp or no?

I'm freaking out over here (in a good way!!) Okay so I have PCOS and don't ovulate. TTC since 2010. This is my 3rd round of Clomid, first at 150mg. (I got my first positive ovulation test, ever!) Im now 13 dpo, AF expected on 18th according to glow. Why am I freaking out? I just checked the test I took with FMU this morning and I have a faint positive...2 days ago was completely bfn so idk whether to be ecstatic or if it's false. I'm gonna retest on Saturday  if AF stays away.