Congratulations on your pregnancy!
Im sorry its off to a stressful start.

Pregnancy tests arent designed to measure the level of hcg in your system, only give you a yes or no answer. So the darkness of the line - while it can be an indicator - may mean nothing at all except that particular test was a bit less sensitive.
Ive found Clear B
.lue to be less reliable than first response too. Thats just my experience, others may say the opposite.

Was it a regular first response test or a first response "early response"? The early response tests detect a lower level of hcg than the other.

There is hope. Good luck!