If you started in spring 2015, then you would graduate after eight semesters after completing fall 2018. So transferring fall 2017 would be at the junior + one semester level (i.e. you have completed five semesters, with three more to go). You may want to check whether each school has a residency requirement that may require you to stay four semesters after transfer, or if your major has enough unique courses at the school that you would need four semesters to complete them all.