TTC for baby #1

Nicki • Going to be 21 years old soon and ready for baby #1
Ok so I had very faint positive a while ago then started spotting had blood test it was negative I only ended up bleeding moderately for 3 days and now have cramps and boobs hurt a little  nauseas. I seen on many forums either you can mistake your ovulation date or the test just doesn't detect some woman until they are far along. My question is should I test again or is it a wast of time? Has this happened to any of you ladies? Opinions please. Also peeing SO much?