first time using the strips help me please!

Lynnjoy

can someone help me underatand how this works is my first month using it and i dont understand why a very faint lime is always their ? i know is negative until is as dark as the control line or darker. also on the BBT is it more accurate taking it oraly or vaginal? i started using the strips right after i finishe my period. any recommendation will be appreciated thanks!😊