Body changes

I was on birth control and was on the last week, the ones that give your your period. I had unprotected sex during that time and had stopped taking them. A couple weeks later i started spotting. I’ve been nauseous for about a month now, drinks i used to like taste horrible, and so many other things. I wasn’t worried about being pregnant until all the symptoms and the spotting. All the tests i’ve taken are negative but i’ve never felt like this. I plan on going to the doctor but i was hoping someone else has experienced something similar to this.