Pregnant or period?

So this past week when I was a week away from my period I took a test when I woke up and a faint half line showed and the next day in the evening I took another to see a negative sign. This morning I tried again and negative. My period starts Monday and usually I'm feeling my period come on but nothing I've had one time that it felt like I was going to start and it only lasted maybe a half hour but other than that I've been feeling a little nauseous and not having much of an appetite like I usually do at this time. I'm confused on the fact that i had a positive sign now negatives. Anyone have an opinion of if I could be or not?