just a little anxious...

So my boyfriend and I prefer to not use a condom during sex, but I'm on the pill and he always pulls out. My last period came on time but was short and lighter than normal. The last few days I've been bloated and had more acne and discharge than normal. Since the last time we had sex and he didn't pull out I've taken a pregnancy test and that was negative. We've only had sex twice since my last period and I'm not due for another 12 days. Am I worried for no reason? Is there even a possibility I'm pregnant?