Missed periods, bfn on wondfo tests

Ok ladies I have a question. I haven't had a period since feb 14,2014(first day) and it lasted three days. I have Tested like five times on wondfo tests and get bfns. What is the normal amounts of periods in a row that a women can skip? Also has anyone gotten a bfn on wondfo and took a different brand and got a bfp? My dr is a jerk and won't see me unless I have a bfp, so please don't tell me to see the dr.