Period was 4 days late, not heavy like usual, cramps on and off entire time also not like usual. Any chance of pregnancy?

Maybe. Maybe not. Pregnancy is the most common cause of a missed period. If not pregnant, other causes of a late or missed period include: excessive weight loss or gain, increased exercising, emotional stress, having an illness, traveling, medicines (especially birth control pills), hormonal disorders, etc… A urine pregnancy test gives a reliable result 3 weeks after sex or 1 week after starting a "weird" period.