Period 6 days late..anyone possibly know why?

Amber • 19 been with my fiancé for two yrs. pregnant with our first baby! Due febuary 27,2015!!(:
Period wasn't due till may 27th but got it in the dead of the night last night it was bright red. For about a week or more my boobs have ached around the edges and the last 3/4 days my nips are super sore/irritaited I have gotten random pains in them also. Kind of needley in the right nip at times. And throughout the month I have experienced random sharp pains in my right hip/pelvic area. I have used the bathroom more also the past week/ week 1/2.  But my boobs never hurt this much before.Is this wierd? Should I be concerned or anything?also my mother had 6 months of full periods when she was pregnant before she could out she was pregnant with me..could I be the same as her? Sorry for the length and if this is tmi..