Spotting and exercise

So last night I finally committed to exercising after about 2 years. Part of that reason was because I was pregnant. So of course I would be very out of shape and when I woke up this morning I noticed my mid section was sore and I had spotted lightly. The reason I'm also worried is because my husband and I did not use protection when we got intimate 2-3 days ago. Could I be pregnant again or could it just be because I finally exercised and that triggered the spotting?