Pregnancy scare? Please help!

December 29 I messed around with a guy I had been taking to for almost two months and he was my first. According to my flow app I had ovulated 4 days before that day but when I checked again it said I had ovulated two days beforehand so I really don’t know when exactly I did before we had sex and yes we did use protection. A week after that I was supposed to have my period and I didn’t get it so I became paranoid about it and took a test and it came back negative. It was still early for any result so I waited again. I’m very irregular when it comes to my periods too. After that test I was cramping and passing clots like I usually do when af is coming to visit but still no period and all of that just randomly stopped. January 16 I was put on the birth control shot and they tested my urine and I asked the nurse and she said wait again and take another test to be sure. So I did and it came back negative so I let it go. Lately though I’ve been having more discharge than usual and it’s like a creamy but watery light white look and feel to it. It can also stretch a bit. My moods have been crazy too and my boobs don’t feel sore but they feel like they slightly swelled. I’m naturally a 42D. Can I be pregnant? I’m only 18 and I really need advice lady’s. Please help