Could I be?

I had sex on the 14th. Got what I thought was the start of my period on the 18th, but was light to spotting. No real cramps at all. What do you think? I don't want to test just yet...we were holding off on TTCing again because we are traveling and before the 14th we avoided each other bc my husband was positive for mono. Sooo we couldn't help ourselves any longer! We didn't kiss much or have sex at all for over 2 months because we were afraid I would get mono!