Could I be pregnant?

Patient: December 25th I had a 2 day light period with no cramps or breast tenderness, normally my period last 5 days and have swollen tender breasts. 2-3weeks later I had swollen breasts and very tender nipples which lasted for a week then disappeared. I also had lower back pain, mainly at night when lying down and a constant very dull stomach cramp. When brushing my teeth I noticed I spat a little blood which never normally happens and my gums felt a little tender but this has now stopped. Is it possible I could be pregnant and conceived before the light period?