I actually go back and forth from liking and hating this drama. I feel so bipolar. This is such a guilty pleasure that I want to forget yet once in a while pops in my head to call me for a rewatch.
But watching this again now, I definitely unsatisfied with the ending.

First off, the good things:
As many reviews has mentioned has similarity with Autumn Concerto (a drama which is dear to my heart), and in which case yes, the plot narrative is definitely the same.
From the secret pregnancy, then the cute toddler kid, with struggling and loving single mom, and a rich jerk baby daddy who has a pretty sophisticated GF. It is like a carbon copy of plot device from Autumn Concerto. I always liked those secret pregnancy dramas with cutie toddlers. I keep rooting for the babies to experience having a full family and their happy ever after.

Sadly for this drama, the bad things:
The happy-ever-after here feels like a bad case of Stockholm syndrome or abused woman who just cant get away from the abuser.
I mean, the ML is one big BIG jerk, who is characterized as smart yet get easily manipulated. For all his brains and heart, he can easily forgive other people who manipulated him, berated him and used him; but then he turns to bite and distrust the FL pretty fast and deep. I get mad at my screen. The worst part is how he conscientiously separated the mother from her kid. That is just wrong.

I keep waiting and hoping for an alternate universe dramaland, where the FL ends up with a kind man not the ML.
But sadly the SML in this drama is the same type of cruel or way worse than the ML. SML is way into the competition with the ML, he uses, hurts and assaults the FL for his own selfish agenda. He should have spent some time in jail. In the end, all were forgiven.
Then there was the mother-in-law who was horrible as a mother and worse as a grandma and just wrong as a human being. Then there father-in-law, who was as horrible as everyone in his family. they were one big lump questionable and cruel people.

I feel bad for the kid on How he will be raised by these people. He grew up with a kind mom for 5 years but after that he will be raised by these tr*sh people. This family doesn't deserve the FL or her kid. But sadly she doesn't realized it, cause she is a doormat of a character. I mean i get that she has some mental issues and easy to be manipulated, but to have a female lead who is weak just makes me so angry.

i wish there was an alternate ending, with her having enough backbone to Kidnapped her kid and goes somewhere away. Or just file for divorce and use ML's brothers manipulation, ML's mom bitchy attitude, and ML distrust in her as the cause her ultimate distress and demand to get a big fat alimony with sole custody of her kids.

Or this totally needs to be a transmigrating drama. She dies giving birth and she goes back to the time before she gets pregnant with her child and makes a conscious choice not to meet the ML and the SML. They are the bane of her sad experiences.

I could not get over the the narrative which was wrong in so many ways. and the acting isn't even to mention. everyone was all kinds of shallow portrayal.

The journey was one roller-coaster, and the ending still feels like a horror train crash with the zombies eating away the mangled disarray of a plot in this drama...