:confused: I had unprotected sex a few weeks ago. I was supposed to start my period a few days after that... Two days ago I had light bleeding (my period is usually REALLY heavy, so a light period is very unusual) what is implantation bleeding and how do I know if this is? It ranges from really light spotting to just a little bit heavier, but its not a constant flow. And then today, it was brownish.? I've never been pregnant before. I took a pregnancy test and it says I'm not pregnant. When is too early to take a pregnancy test?

Here is the info you requested on Implantation Bleeding. If you are bleeding the likelihood of you being pregnant is slim. It is possible, but slim.

The most accurate time to take a pregnancy test, any pregnancy test, is approximately 1 - 2 weeks after your period is late as it takes this long for the pregnancy hormone called hCG to build up in your system.

Also remember to take the test using first morning urine as that is when the concentration of hCG is the highest.

You can take a test anytime after you have missed a period, but some women take longet to get pos results than others. If you have been bleeding pregnancy isn't likely, but if you are worried re test in a week or so and see what happens.