Could Lower Back Pain,abdominal Pain And Loss Of Appetite Indicate Pregnancy?

i am on the implant and have been for the last 15 months i just wonder if it possible for me to get pregant i have been passing clots and i have been doing this since i last had intercourse with my partner around 4 weeks ago i have lower back pain and abodinal pain and i have lost my appitate also i sometimes feel sick after eat