Do I pay for the clearblue?

Hollie

Had my implant removed last month and have been on the pill. Period overdue 14 days. Took a test and it said negative but it was one of those cheapies. Currently on day 6 of pill break and no cm, no pms symptoms and no sign of af. Do I invest in a more expensive test to make sure or just put it down to hormones being mucked about? TIA