Quick question

So my boyfriend and I had sex on the 14th of Jan and a few days later I was in the ovulation days. The 22nd was my fertile day, and now it’s day 3 and I still don’t have a period and I’ve been constipated, tired, and Nauseous. What is going on? I’ve used the pregnancy calculators to see when I would be due or how far along I am and it says 4 to 5 weeks