Did Plan B Work?

[ellio22]

Hello,
I have a question about the Plan B (One Step) Pill. This was my first time taking the pill (An accident happened in which the condom broke as he pulled out), and I'm feeling quite nervous about it's side effects and when to expect my next period. Around 4 days, I began to bleed as if it was the first day of my period, and on the 9th day I had some slight spotting. I took a pregnancy test (E.P.T, one of the early pregnancy tests) twelve days after the incident. The test seemed defective, due to the evaporation line showing up and causing my test to be invalid. I took another test a day later, and I saw that the negative line was slightly darker, making the test more accurate. It's five days before my period now, and I'm having slight cramping and slight bloating. This is normal for my cycle's symptoms. I'm also having white discharge (that dries white in my underwear). Is there anyway you can give me an ease of mind about me not being pregnant? I heard if you bleed from Plan B, that you are not pregnant. This was my first time taking any sort of emergency contraceptive. Will this affect my cycle? Also, I'm hoping after I get my period, to go on a low dose of birth control. Will this make me gain weight?