Why is your mom so mean?
Its because they hate you!!
If your stomach starts to get tight and your not doing any exercises does that mean your pregnant?
Answer No this doesn't mean your pregnant.
Your nipples are sore and your stomach is starting to grown does this mean that your pregnant?
Possibly but this is not a very good symptom. Take a pregnancy test
Does that line going from your belly button to your vagina mean your pregnant?
No, it doesnt :) dont worry
What does it mean when your not having cramps and your on your period?
Not everyone gets cramps, and they aren't always the same, sometimes fierce and sometimes non-existant. There is nothing to worry about, this is absolutely normal.