Could it be?

I ovulated about three weeks ago. Not sure exactly when, because Glow keeps changing my days when my period doesn't come. Normally my period is a medium flow, & very red in color. This time, it's almost spotting & it's light pink, a color I've never had before. I've had some nausea after eating certain foods. Took a ept test yesterday which was negative. Could I still be pregnant?