weigh gain..

Ok so long story short I think I'm pregnant I've had a bunch of "symptoms" although I still had a lightish period. The thing that drew me over the edge was I've been 103-105lbs for about 4 years like it lightly flunctuates. And I'm now 108-111 which is a lot for like only a month I'm going to test soon. Just wanted to know if any of you experienced something like this.