Is Pregnancy Possible Through Pre-ejaculatory Fluid?

Me and my boyfriend messed around back at the end of July, he only had the tip in (unprotected) and never cam. Although I've read you can become pregnant with pre-*** but I also know the chances are very lowe. I've been having pregnancy symptoms lower aching/sharp abdomen pain and in the groind, breast feel fuller with more noticeable bumps on nipples, constipation, white clumpy, watery, and cream like discharge, acid reflexes, and stomach pain/boating. I had my period last month in August on the 27th that lasted 3 days which isn't too out of the norm for me. It was very heavy with harsh cramps the first day then off and on spotting the last 2. I've taken 8 urine pregnancy tests at home sense then and 2 at my doctors including a blood test. They all came back negative but I've also read that woman that have had pregnancies without any HTC and had periods.

Also I did take treatment with a high dosage of antibiotics for an infection, maybe that's playing a part?

So could I be pregnant or could it just be my hormones out of sorts from the excessive stress? Should I trust the tests? I'm an excessive worrier/anxiety and I just can't stop thinking about it. It's effecting my everyday life, can't eat, sleep, work, it takes up most of my thoughts.

Any advice or help talk me threw my nerves and convulsion would be greatly appreciated, thank you!