Netti- i know that i have felt dull period like pains in early preg and it has been really just my body adjusting.
Did the line get lighter in your hpt than it was before? Could just be the time of day- i know your levels are higher first thing in the morning- could it be that this time when you tested it was later in the day? I would only be worried if you did a hpt and there was no line at all...

Your fears are understandable though and if you feel you need extra bt or what ever to ease your worry- do what ever you need to do!!!

Good luck and i hope that all is well!

SB