What could be going on with me?

So last month I had a light period (?), that at first I thought was implantation bleeding, but all my HPTs came back negative. This month, I'm a week late already and I don't even feel like AF is coming. I don't have the symptoms (cramps, backache, etc) of her or anything. I'm in a long distance relationship and only saw him for three days so I know exactly when I would have conceived. I haven't taken a hpt in about a month because I don't really think it's pregnancy even though at the beginning I was convinced it was. I had a ton of weird symptoms going on. Just wondering what else could be going on with me. I'm gonna make an appointment to see my gyno this week.