Since they're 10 mIU I'd wait a bit to use the FRER. But I'm a POAS addict so that's very strange advice coming from me
The day I got my bfp - the ic was barely visible- thought it was an evap possibly even though showed up in time. I held my pee and didnt drink from noon to 4 pm and tested with other tests - and got much darker lines (on FR & other brands - didnt have other ic's left to see if the issue was the ic's, fmu, or just plain got darker) The tests were all the same day though - I even had positive digi that afternoon - even with a barely line on ic (looked like yours)
Congrats to you!!!