I cheated on my partner...

I got mad one night several (SEVERAL) months ago because I felt my partner was cheating and I found a bunch of porn on his xbox and phone....and I met up with an old fuck Buddy and had sex 
It was only once and that same night I regretted even meeting up with him. 
Fast forward to now
I'm pregnant with my boyfriend and we're getting married 
Should I tell him I cheated before we get married so he has an option to choose to be with me ? 
UPDATE: IT WAS IN THE FIRST TWO MOMTHS OF A FAIRLY NEW RELATIONSHIP 
HE WAS GOING OUT EVERYNIGHT DRINKING AND DOIMG COKE AND IT UPSET ME HE WASNT GIVING ME THE ATTENTION I DESERVED BUT WAS GETTING HIS WITH FUCKING HOES ON THE COMPUTER 
AO I FUCKED A FUCK BUDDY OF MINE (NO IT WASNT EMOTIONAL , he fucked me in the backseat of his car at a mall
I just needed to get the frustration out 
Fast forward a year we haven't had any troubles 
I've been loyal as hell 
And he's been off drugs and drinking for months now- almost a year.
I was in a bad place because my boyfriend was dependent of everything but me 
We have fixed our issues but he doesn't know I slept with someone 
Once 
For not even 10 mins and I cried the whole way home because I felt so ashamed that I even did that 
ALOT OF YOU LADIES BELIEVE YOURE SO MUCH BETTER THAN ANYONE ELSE, BUT GUESS WHAT YOURE NO SP STFU AND DONT BE POINTING FINGERS BECAUSE THREE POINT BACK