I have my last period on August 23 to 28, then on September 1 my back start to ache, I thought its just stress or I'm just tired but it lasted for at least a week. Then on September 5 I got a light spotting. I started gaining weight because I'm always hungry. I crave for fruits (just for the info, I don't like eating fruits before). My back still aches and my breast. I also feel dizzy during afternoon. And just September 14 I have a light spotting again but it stop. And now September 15 I have a light period. I'm just worried because its too early for me to have my period and this isn't happen to me before. And also two weeks before I have my period last month I am sexually active with no protection..
I hope someone can give me some good answers

There's no way for us to tell if you're pregnant or not. The only way to know is to take an hpt or go to the doctor for a blood test. It may be too early to test yet, so I would wait until you are indeed late for your next period, and if you don't get it try taking an hpt using first morning urine.

There are many things that can cause spotting or a change in your period, pregnancy is only one of them.

You could also go to your doctor. It's always a good idea to let your doctor know when something abnormal is going on with your body.

Good luck.