Could I Be Pregnant???

The last period I had ENDED on September 20th. I had no period or any spotting in October. I have really sore nipples. Headaches and backaches often. I also have a weird pressure feeling in my pelvic area. I took 2 tests a couple weeks ago and they're negative. I took two more yesterday, they were really faint and only one had a little color to it. What do you guys think??? Should I wait and take another one??