It is okay to have sex! Just make sure your partner isn't being to rough that's all. You don't want to be bleeding either. If you are experiencing implantation bleeding wait once it's done and has passed to have sex. It usually only lasts 1-2 days anyways so not too bad

OK thank you.. when is the best time to take a pregnancy test

Unless your high risk, and/or your doctor tells you otherwise.

Yes unless you're bleeding