Can I still get citizenship if divorce is not yet completed?

A U.S. Lawful Permanent Resident may become eligible to file an application to become a naturalized U.S. citizen as early as 90 days before reaching 5 years from the date he became a Permanent Resident, and this is true regardless of whether he may have a pending divorce case or even a concluded divorce. Note that if you obtained your Permanent Resident status by virtue of being married, such as would be the case if your wife was the primary applicant and you were the derivative beneficiary in the process by which you both became Permanent Residents, then the USCIS could inquire to see that your marriage had been bona fide notwithstanding that it ended in divorce. With a child together, as shown by both parents on the child's birth certificate, I would anticipate that showing the bona fide nature of the marriage would be relatively straight-forward. There are other requirements for naturalization eligibility and it would be wise to work with an immigration attorney for the application process.

Yes. But you might have to wait longer, and might have to explain your life events.