It's OK to show a loss in your first year (or second, or third) of being self-employed in fact, probably many or most self-employed do. Maybe not in mystery shopping, because overhead is lower than in many start-up endeavors, but you don't need to show a profit....
I'd take the phone expense this year, if it were me.... But it's not! In the event you decide to take it next year, you would indeed expense the cost according to the percentage you use the phone line for business purposes.
I learn something new every day, but not everyday!
I've learned to never trust spell-check or my phone's auto-fill feature.