Spotting After Stopping Birth Control. Headache, Cramps, Nausea, Sensitive Breast. Pregnant?

I didn't get my last shot for a month and a half. I spotted for that whole month. Everyday. I had sex a couple times in the last two weeks. The last time, the day after I felt cramping and then I started having headaches, nausa, feeling hot , sensitive breast and cramps. I went to my dr to get bc pills and told her what was going on and took a test. Came out negative but she said it could be cause my hormone s levels aren't up and early stage of pregnancy. So take a test in a month. This was on last week on Wednesday and start my pills that day too. Two days after I completely stop spotting and spotted light brown and once red pink color for three days and went away. Now my breast feel heavier and hurt when touched. Every time I eat I feel nauseous. Could I be pregnant or is it bc symptoms?