Hey, around the 17th and 27th of December I was on antiboytics and on the pill at the same time but was not using a back up methrd like comdom with my boyfriend we had sex a lot between them dates. I do want to get pregnant! Then I started to get sore boobs it comes and goes but I still havt blue vains on my boobs.I took to pregnancy tests came out negtive. But it was really ealry on Friday I took a blood test come negtive as well I'm due on my period today but not yet resvied it. I went onto an ovaliton caldener done all my working outs said that a test my work on 7/1/08 which is today's date. So may the blood test be wrong ? I always come on my period on a Monday and I have not got it could you give me some answers in what's going on people say take a test but they keep coming out negtive as I was not meant to test till today could I still be pregnant ?

Hey, around the 17th and 27th of december i was on antiboytics and on the pill at the same time but was not useing a back up methrd like comdom with my boyfriend we had sex alot between them dates. I do want to get pregnant! then i started to get sore boobs it comes and goes but i still havt blue vains on my boobs.i took to pregnacy tests came out negtive. but it was really ealry on friday i took a blood test come negtive as well im due on my period today but not yet resvied it. i went onto an ovaliton caldener done all my working outs said that a test my work on 7/1/08 which is todays date. so may the blood test be wrong ? i always come on my period on a monday and i have not got it could you give me some answers in whats going on people say take a test but they keep coming out negtive as i was not ment to test till today could i still be pregnant ?

If you have a 28-day cycle (a lot of women don't) and your period is due today, you should be 4-weeks from your last menstrual period and have a 4-week gestational age if you were pregnant. It would also mean that you conceived about 2 weeks ago (which would fall into the window you are concerned about).

IF you were pregnant, you would expect to have a detectable bHCG (protein/hormone tested for with pregnancy test) at this point. You may still be pregnant and just be really early if you conceived more than 14-days after your last menstrual period.

I would advice waiting a week and retesting yourself if you still do not get your menstrual period.

Hope this helps. I have included a rough reference range below. The detection cutoff is usually 25 mIU/ml for urine and slightly lower for the blood/serum test. Less than 5 mIU/ml is considered 'not pregnant'.

Graphic:

(LMP) I-------I-------I (Ovulation) I-------I-------I (Menstr. Period)

LMP = Last menstrual period.
Ovulation usually occurs 14-days after your LMP. And is when you can get pregnant.
(each dash would represent 1 day and each 'I' a week block)

Guideline to hCG levels during pregnancy:
hCG levels in weeks from LMP (gestational age)* :

3 weeks LMP: 5 - 50 mIU/ml
4 weeks LMP: 5 - 426 mIU/ml
5 weeks LMP: 18 - 7,340 mIU/ml
6 weeks LMP: 1,080 - 56,500 mIU/ml
7 - 8 weeks LMP: 7, 650 - 229,000 mIU/ml
9 - 12 weeks LMP: 25,700 - 288,000 mIU/ml
13 - 16 weeks LMP: 13,300 - 254,000 mIU/ml
17 - 24 weeks LMP: 4,060 - 165,400 mIU/ml
25 - 40 weeks LMP: 3,640 - 117,000 mIU/ml
Non-pregnant females: