Seeking Your Advice Asap New Member!

Hi everone,
i am new to this site. Thankyou everyone for the wonderful supportive information with your posts.
I have learned a lot...

I am trying for my 3 child my cirles are 28 days and I am very regular.
My last period was on 8/12/05 or 13/12/05 if it was (13/12/05 I figured that I would have overulated on 27th dec.
My husband and myself have unproteced sex on 24, 25, 26, 27,28,29,30dec.
I have been experencing very sore breasts which are heavy when I take off my bra and are sensitive to touch at times, I have also been getting quite strong cramps in my pelvic region the last 3 days.
Feeling a little off colour nausua without throwing up.

I have taken 4 home pregnancy tests but all have come out neg .... Is it that I may be testing tooo early??

I figured my period is due on 10/1/06

what are your thoughts???? Could I be pregnant?? Even having had 4 neg tests. Or do I need to wait another 6 days to know for sure
your thoughts would be very much appricieated.

Lisa