I Had Fever For 2 Days Last Week (Sunday And

I had fever for 2 days last week (Sunday and Monday), stayed home on Tuesday and went to work on Wednesday. I had to stay home again on Thursday and Friday because of fatigue and congestion. I've been fever free since then but still is a bit congested. I'm planning on going back to work tomorrow. I was prescribed Tamiflu on Wednesday but did not take it then because I didn't have the flu. Is is okay to take the Tamiflu now for flu prevention?