Can i take 400mg ibropruphen when i am on 500mg amoxicillin and 400mg metronidazole ?

Yes: Take all medications as directed by your prescribing physician. In fact, always tell each & every health care provider that you see about everything that you take, both medications (prescription & over-the-counter) & dietary supplements. I found no drug-drug interactions at http://www.drugs.com/interactions-check.php?drug_list=187-0,1310-0,1617-0. Get well soon!