Am I just being paranoid?

I had sex on the 22nd. We didn't use protection. He did pull out but I wasn't sure if he pulled out on time bc I felt wet. But He said I was already really wet. Anyhow I had recently switched BIrthcontrols but straight after my last sugar pills I started taking my other birthcontol pills. I had sex probably 2 or 3 days after I started taking my new pills. Ever since I started taking my new pills I've been really nauseous and bloated. I have gained weight but I think bc I haven't been eating like I use to. I really don't want to be pregnant. Am I just being paranoid of being pregnant? Do Yall think I'll be okay?