Mortgage end of fixed term

I drew down on my mortgage in April 2016 and fixed it for a 3 year term at 3.2%. I expected that the 3 years would be coming to an end around April or May this year but I just found out it won't be until July. I don't understand how it works as it was my understanding that the fixed term would be 3 years from drawing down/first payment?
I am eager to re-fix it at the lower 2.3% rate I am now eligible for...

Thanks in advance for any insights!

Ulster bank?

Yes how did you guess? Is there something I need to know here?

That's how Ulster Bank do it. Its fixed to a specific date, rather than for exactly 3 years.

It should be on your documents that it's fixed until a date, but I'm not sure how clear they make it.

That came as complete news to me and makes no sense whatsoever really, does it? But I guess at least now I know...
And for the record they absolutely never explained it to me and I am one for asking lots of questions. I guess it never occurred to me to ask '...and what do you mean by 3 years, exactly'

the rates are generally known as 1,2, 3 or 5 year fixed rates, but they will have detail on the rate that says e.g. 3 year fixed at 3.2% until 30/06/2019.
if you requested the fixed rate from before you drew down the mortgage, then the rate on the loan offer should reflect this and should have the details.
if you want to look after your mortgage in a more relaxed way, Ulster Bank now have an online service for their mortgages.

https://digital.ulsterbank.co.uk/personal/mortgages/manage-your-ulster-bank-mortgage.html

or if you want to search for the link yourself, search in the ulster bank website for "manage my mortgage". you can check repayments, rates, over-payments, new rates, and request documents from that website now.