I'm sorry that this situation is making you scared. I'm glad to say that there is really no way for you to have gotten pregnant that way. Sperm is not carried through urine and would not survive on a toilet, or the vigorous handwashing. Sperm needs to be inside a body to survive and dies quickly outside of a body. Unless you've had sexual intercourse lately it's highly unlikely for you to be pregnant. Periods can sometimes change as we age, or because we are stressed, or hormone fluctuations. Is this new job stressful for you? I know that having period changes can be worrying. I hope this helps you feel better.