Pregnancy infection. Is she pregnant?

Sir/mam I had an intimate moment with my partner on december 13 2017 it was protected i was using protection and no intercourse happened but for further protection she ate a contraceptive pill ..and we did a urine pregnancy test after 24 december and it came negative. She has had two periods since but this month she has cramps but no periods instead she had a little brown discharge and very light bleeding spotting , we again did 2  urine pregnancy test one at noon and other the next day morning with first urine they both came negative. Problem is that she is still getting spotting its the 7th day since it first started and has burning sensation in her lower tummy and sometume in her vagina.. Is she alright? . Is she pregnant ? What could be the reason please help. Thankyou