Pregnant 9 weeks PP?!

I am so stressed out writing this... I just had my two month old on December 4th. I EBF and haven’t gotten a period yet. I had sex for the first time PP on Jan. 10th. We didn’t use protection but he pulled out. We’ve also done it several times since with no condom (because we’re idiots.) for the past week and a half I’ve been really hungry and sleepy (normal for nursing new moms) but I’ve also been super nauseous which just started. I took a test last week that was negative and I feel like I wouldn’t be experiencing these symptoms without a BFP right? I need help, I do NOT want another baby right now