Pregnancy test expiry date & when is too early to test?

I’m currently 10dpo

My boobs are tender and at around 6/7dpo I had light cramping like AF but much lighter.

I have a first response test that says it expires 1/18

Does that mean I can use it until the end of this month, or it expired at the beginning of the month?

Also what DPO am I more likely to get BFP if I am?

TIA! x