VERY light line not getting darker (PIP)

saintpaulJess

I tested at 10 DPO and it was negative.  Yesterday, at 11 DPO, my temp went up and I tested again.  I got veeerrrry light lines on two Wondfos, but two FRERs were negative.  I figured I just needed to wait a day.  This morning my temp went up again, but the Wondfos are even lighter.  I haven't used an FRER today because I know it won't show up and don't want to see a negative test again.

I'm on Prometrium for low progesterone.  Last cycle I was tested at 7 DPO and my progesterone level was a 6.9.  The doctor said she likes to see at least a 12, and put me on 100 mg Prometrium and told me to come back at 7 DPO next cycle.  That was Monday and it was only an 8.1.

I'm afraid this may be a chemical pregnancy.  I haven't even told FI yet, because I don't know what to tell him.

The top three tests are from yesterday and the bottom two are from this morning.  I know I'm going to find out in a matter of time, but has this happened to anyone and it wasn't a chemical pregnancy?  I want to feel hopeful, but it's hard.