back again...

hello ladies, I'm in some need of help again. I was supposed to start my period on the 18th this month, and I have very regular periods. I've been feeling off and I've taken a few tests (two before the 18th, and one today) and they were all negative. all I've been getting is a crazy amount of cm (more than normal and I check it daily) I'm just wondering if there's any chance I could be pregnant and I just don't have enough hcg for the tests to detect. I've been having some symptoms like sore boobs mild cramping slight bloating and what not, we've been ttc for 8 months now and we really want a little one and I just don't wanna get my hopes up...