Vacation & Pregnancy Possibilities.

Jessica
Iam positive I ovulated early (a week) Iam suppose to be the most fertile this week but have had no positive ovulation tests. However I did two days last week. We've been BD'n pretty much everyday for the last 2.5 weeks so hopefully after this long grueling wait things will be positive. I've been noticing a bit of cramping in my lower abdominal area! 
My biggest concern is that Iam suppose to get AF on the 15th of April. Which is the day before I leave for 3 week Caribbean vacation. How early could one test? I would like to know before I go down there.