Bbt thermometer concern

Tiffany • Mommy of two boys and wife to a loving man #blessed
I woke up today with a crazy reading of 98.00 (just took last day of clomid) and I'm cd 8.  Then I waited about 2-3 mins to test(out of curiosity) and it read 97.45...??? Then 97.00...then 97.35...... MY question... Is it time to buy a new one?  I've had it maybe 2 months.  Could the temps be crazy bc of thermometer or am I having a crazy cycle???