I've got a 6th gen, 4 door, 4 cyl. Last week I took off my 17's for the winter and put on my stock 15's. The car is dropped on Eibach's. When I had the car dropped and new wheels put on, I had an alignment done and everything was fine. Now that I've taken off the 17's and put back on the 15's, it seems like my alignment is out of whack. the car seems to want to pull to the right most of the time

I've had the wheels properly tightened according the to lug pattern and properly torqued as well. Do you need to get an alignment done everytime you swap wheels? So does that mean I need to get an alignment done now and then when it gets warm and I put on the 17's again, I'll need another alignment?