Some say to add 7 months to your age of conception, other's say 2 years. Either way, I conceived just before my 20th birthday. A month before actually. So does that mean it's a boy or a girl by the calendar?

Yes I know it isn't 100% but it's fun! And usually more often than not it is right!

if you concieved a month before you're 20th birthday, then your lunar age would be 20. Some sites automatically change it for you though !