Hello, I Have Never Had Actual Sexual Intercourse But I

Hello, I have never had actual sexual intercourse but I have I guess you can say messed around with guys. This past friday (4 days ago) I did just that with a guy and he ejaculated on my thigh fairly close to my vulva. I then wiped off with a towel, fixed my hair, etc. I do not recall if I washed my hands. Some time later (perhaps 15-20 minutes later) I inserted a finger into my vagina. Is it possible that I could be pregnant as my hand had come in confact with semen when I wiped with the towel. My period was supposed to arrive yesterday and it still has not, and I tend to be pretty regular. Also as of the day after this encounter I was experiencing a lot of milky discharge, the kind I usually have around the time of my ovulation. This was unusual because I had ovulated 2 weeks ago already. I know that this type of discharge is one of the first symptoms of pregnancy. Do I have reason to worry that I am pregnant?