I Have Been Recently Been Having Bad Heartburn, My Doctor

I have been recently been having bad heartburn, my doctor prescribed omeprazole for me 40 mg which I take once a day and it has been helping with the burning pain. I am also getting an endoscopy in a few weeks to see whats going on. Now I have a bad cold and would like to take alka seltzer cold tablets.Is it safe for me to take it this one time? The package says do not takeif you have an ulcer or stomach bleedingwhich I havenot been diagnosed with this as of yet.