Pregnant?

First of all, my periods are never the same. Sometimes they are early, sometimes they are late, I've skipped periods just a few times. I had my last period June 4th and it was a regular period. I wiped a very light pink 4 days ago. It lasted all day. Next 2 days was a darker pink. Enough for tampons but still wasn't red and wasn't as heavy as my normal period. Then it got lighter then the last day I wiped a light brown. Now it's gone. Me and my husband have been sexually active and have been trying to conceive. I don't know if it was implantation bleeding or just a light period from stress. Could I be pregnant? I was planning on taking a test sunday.