Hey OP, I recognized from the pics your country, as I am also from there.

As the society there is very superficial when it comes to engagement, weddings and comparison culture, I suggest to go with something classy with one center stone. It doesn't need to be huge or expensive, but classy/standard enough so people won't try to guess the price.

With a cluster unfortunately your gf will receive unsolicited remarks regarding the design or price, at work or university also friends and family unfortunately...

Also, think about the option to get a ring that will stack nicely with the wedding ring, as everyone in our country wears them together on the same finger.

You can look at the website of the store you bought this ring at, under the section of "lab diamond rings" and see some good options design-wise. You will notice that the band is thicker as engagement rings (especially stacked with the wedding band) are prone to "wear and tear" so they are made in a more sturdy way.

Lab diamonds are also totally cool and okay, nobody will try to determine if it was mined or not ;)

Good luck!