Thank you everyone for your replies.
I got sick promptly after my exam.
I'm sure the stress didn't help.
And I do believe that yes, it's the fact they did become intimate first and then told me.
A day later.
Because they knew I was angry and they didn't want to deal with it so they didn't tell me.
So they figured if they let some time pass it would be fine.
I already figured it was what they did.
And they knew I was irritated when they left so they made any excuse to not contact me.
And I know it for a fact.
to move on now