Advice? Potentially Pregnant?

Hi all! I'm a little confused about my June cycle. I'm looking for advice to see if this has happened to anyone else, and to see if this is truly a sign of pregnancy. I'm on a very consistent cycle. eve is typically on point with my schedule, and I was due for my monthly friend this past Saturday. My significant other and I do not use any birth control; however, he doesn't ejaculate in me. I ovulated the second week of June, and we typically have sex once or twice a week. On Saturday, I didn't begin my period, but I had a light brown discharge. The flow was extremely light and lasted about a day and a half. I haven't had any period symptoms or signs of pregnancy. The only thing that has happened that could potentially be an additional sign is that I've been slightly light headed. Today I had a white mucus discharge, which I thought was my period beginning, but it wasn't. I did a little research, and it was recommended to take a hpt 3-5 days after the discharge. Can anyone maybe help me sort this out? Please let me know if I need to provide any additional information! I appreciate your time in advance!