you didn't mention whether your periods are regular or not,
in case of regular periods, if you are pregnant by this time you might have got urine pregnancy
the other possible causes for your symptoms are,
-hypothamo pituitary axis disturbance due to stress and strain or due to drastic change in weight,
because of this increased prolactin
secretion can occur which might have led to sore breasts.
-spurious pregnancy: thinking continuously about pregnancy and being extreme desirous of pregnancy can lead to symptoms of pregnancy in its absence.
so you consult your gynecologist, get one ultrasound
, estimation of prolactin levels and hormonal
assay for thyroid
hormone which will possibly find out the cause.