pregnant or not

I have a question: I have been off my nuvaring for little over a month already and have had a normal cycle. My fiancé and I had unprotected sex during my ovulation days which was last week on 3/17 and 3/18 and I noticed this week on 3/20 and 3/21 I started getting sore in my breast's, very very fatigued and nauseousness. I am on vitamin D tablets which aid in helping my energy level and I work out 4 days a week so these symptoms are not usual for me. My period is not here until April 1st, so I am wondering why I'm feeling like this. I have 2 kids but its been 9 year's and I don't remember too much the protocol for symptoms of being pregnant. 😊 any help or thoughts would be greatly appreciated.