You are not pregnant, your hand was dry.
Your period came, which means, that all the nurtiens that feed a fetus when an egg is fertlized has been washed away. That's why we get periods. It was loghter or weird because you were stressing yourself out. But it came, so you are not pregnant, and there is no chance you could have become pregnant when your hand was dry.
When women are pregnant, they dont continue to get their period, they get something called Break-through Bleeding. Different than a period, OR they get implantation bleeding for a couple days.
The discharge was from your period.
Some women who obsess over thinking they are pregnant, actually GIVE themselves the symptoms of pregnancy, when they aren't pregnant at all. Which is what it sounds like here. Your are over reacting about this, if your hand had wet semen on it, there could have been a chance, but it was wiped off and dry and the chances of getting pregnant that way -if it was wet- are very very low.
You should get on some birth control, so you dont worry about this.
OR abstain from having sex at all, until you know all the risks of getting pregnant and how to engage in safe sex.