Same thing happened last year! It was yesterday.
If the same thing happened last year, and you didn't tell them how sad or disappointed it made you feel, added to the fact you don't make a 'thing' of birthdays between you and your dh, then presumably they have no idea that you want them to celebrate, or even acknowledge your birthday.
However if you do want to celebrate your birthday, then how come you don't have conversations like "Who wants to come for a meal for my birthday next week?", as I, and all of my family do ?
Poster will say you shouldn't have to - and I don't disagree, but all of my family manage to remember birthdays as we always made a little bit of a fuss of all of our birthdays for all the years they lived with us.
If you haven't done that, but want to, you can choose to stay quiet and be upset each year or you can talk to them about it or you can sort something out yourself.