Is Pregnancy Possible Through Pre-ejaculatory Fluid?

I am worried I may be pregnant. I will give as much detail as possible: This is the first month I ve been off birth control in a year or so. On the 17th day of my cycle, I had sex. At first, we used a condom. Then we took a small break. He used the restroom. After about 5 minutes, we started again, but this time without a condom in the beginning. After about 1 minute of penetration without a condom, he put one on and we finished with one on. It is now day 21 of my cycle. I have really sore breasts. I don t have any other symptoms, but I am worried about the minute of penetration without a condom. Could his precum get me pregnant? Or could he have still had semen on his body that could ve gotten me pregnant? If so, what can I do to prevent pregnancy? I know it is too late for the plan B pill. Thank you in advance.