Basal Temp thermometer a bust, I think.

Hello everyone. I recently bought a basal thermometer to start taking my temperature every morning along with doing the OPK and the numbers are not changing. My opk is showing that I'm ovulating but the BT has not shown a surge in temperature. It is bouncing between 97.33 & 97.42 everyday with no change or rising numbers. My question is has anyone else experienced this or am I doing something wrong? This stuff is so complicated and frustrating. Please HELP!!!!!!