My Guidance Counselor Told Me that My Weighted and Unweighted is a 3.5?

Totally depends on your school’s grading scale and how they weigh courses.

Usually there is a range for GPA. The 87 could be at the very low end of the range for a 3.5 in your school and the 90, at the very upper end. Both would still yield a 3.5.

Be aware that most universities will do a deeper dive of your transcript.