Important Question!

Yesterday, my boyfriend and I took advantage of our alone time with each   other, since we've both been pretty busy recently. We are in our late teens and have been dating for quite some time, and we went the furthest we have ever gone yesterday. We engage in mutual masturbation, but we do not plan to have sex for at least a few years, and mutually masturbating each other is the only sexual act we have done thus far.
​He had been fingering, stimulating mostly my clitoris but also occasionally penetrating me with his fingers. I began to touch his penis, and he had pre-ejaculate oozing from the head of it. I stroked him, and I reached down to get some of my wetness with the same hand that I used to touch him with (a hand that had small amounts of his pre-ejaculate on it) in order to lubricate him more easily.  He continued to finger me, and I stimulated him as well.
​My concern is that some of his pre-ejaculate may have come into contact with my vulva and/or the inside of my vagina. I am fairly certain that before our encounter he had urinated, and I am also fairly certain that he had not ejaculated before our encounter (I am 100% certain that he did not ejaculate DURING the encounter, and there was absolutely no semen, just small amounts of pre-ejaculate).
​According to Glow, I had a 7.8% chance of fertility yesterday, as my period had just ended two days before. My next period is due in about 20 days. Do you believe there is any cause for concern regarding pregnancy?