St5 now taking home less per month than before new deal agreed

Having looked at my payslip this month, it looks like I now take home less as a new st5 than I did as an st4 last year… I think this is because of increased student loan and pension payments. I will get the BMA to check my pay as this can’t be correct.
I’m on a full time anaesthetics rota with nights and 1 in 4 weekends same as last year.
Thanks Jack!!