I need some help.
Okay my last period was Dec 8, 07 and was suppose to come on the 4th of Jan. But its now the 7th. I'm getting cramps but still no sign of blood. I asked my sister did she get any cramps when she got pregnant and she said no, She didn't feel anything. I'm never this late.

And have a reg 28 days. But for some reason lately its been jumping around a lot. for example.

Oct 13 was the first day of my period.
Nov 9th was the next time I got a period. (28 days)

Now heres the funny part, the next time I was suppose to get it was Dec 6. But got it on the 8th instead. But like most females the can be late or early by a few days.

So I counted from each day.

From the 6th to now I would be 5days late.

From the 8th that'll make me about 3 days late.

Was should I do? Could I be pregnant?

And yes I'm sexually active...But a few nights ago we did use a condom and cleaned and re-used it the next day...I know (Nasty) but it was all we had.