sharon,
so you are still breastfeeding but have your menses! i see... i think we should all know that having menses doesn't really mean that we are ovulating.
try testing about 10-11am in the morning. and everyday must test at the same timing. don't drink too much water prior before that.
and when you say negative i am assuming that you get no line on the kit? =) anyway, a positive kit will show 2 bands with same shade or the test line with darker color.
how long is your cycle? on which day do you start testing from? maybe you can start testing earlier?
try observing cervical mucus while using the kit together. when you see transparent water mucus, it indicates fertile period.. and when the O happens, you may experience transparent stretchy mucus something similar to egg white like that! =) check when you go toilet pee. can either use toilet paper when you wipe or use fingers.
anyway, the fastest way to see if you are ovulating is indeed to go to the gynae for a scan! =) they are able to see the follicle size and tell you agaration when you will be ovulating yah...
a few mommies here have gone thru this and they can advise you better.
another way to see if you have ovulate is to take bbt, that is your #1 sleeps through the night. =)