Depo shot making me nervous

Hey,

So four months ago I went onto the Depo shot, discussed everything with my doctor and ensure I would be protected. My doctor told me there would be a two week leeway to get the next shot as I had a holiday planned when the next shot was due 4/01. So as planned i went to get my shot on the 16/01. I had a different doctor and they were concerned about the time off bc (yes there was sex during time). Test at doctors said negative but I mean it had only been a week or so. I'm getting nervous now because I'm have what could be symptoms of bc or pregnancy. When I had my first shot I had dark spotting for two/three weeks a week after the shot, this time I have had very bright spotting for three days after the shot. I've been exhausted but work has also been crazy. The thing that's worried me a bit is I haven't gained any weight but it's like my hips are wider or something because my jeans and shorts are fitting tighter and snug which they haven't done in a while (trying to lose weight). I am going a bit crazy over it, on the one hand there are explanations for the what I'm feeling but just wondering if anyone has gotten pregnant after their first shot in that window?