When should I test?

My period is in 7 days. I've always been on time, give or take a day, but never extremely early or extremely late. I noticed when I went to the restroom that I was bleeding and it was as brown as brown can be just as I've been told to look out for. I know that's tmi but my husband and I have been trying for 3 years for our first child. I am not sure what to do at this point. All I keep asking myself is if this is implantation bleeding or is something wrong with me. If I were to test, how long should I wait to do it?