How accurate are the blood tests?

iVillage Member
Registered: 09-24-2003
How accurate are the blood tests?
4
Tue, 09-30-2003 - 12:21am
Hi! I am new on these boards, but I really need some advice. I have had 2 kids and we are now trying for#3. My last period was August 26, so I was supposed to O 9/9-9/12 - Well I thought for sure that we had succeded but all the HPT showed negative. (with my first 2 kids they were positive right away) I finally went to my Primary care Dr and asked him to do a blood test to show that I was preg. He called a few hours later and he said it was neg! I am over a week late and I am so confused and way bummed. I really thought that I was preg. Has anyone had a false blood test before? Any advice would be appreciated. Thanks! Andrea
iVillage Member
Registered: 09-22-2003
Tue, 09-30-2003 - 7:04am
Hi Andrea !

Blood test are very accurate.You've mentioned that yo're one wee late andyo didn't get yor AF yet.Is your period regular/irregular? how many days is your cycle?

Lets suppose that you have regulat period and the cycle is average 28-30 days. Your last LMP was 26 Aug.then your period should be due within 22-24 Sept.

There are two kinds of blod test.Qualitative blood test that either says negative or postive ( I guess that's the one you did at dr. ofice) and the other is quantative blood test that shows the exact level of HCG in blood even if one unit only.

The blood test you've done can detect pregnancy ( if happened) on the day your period is due or if you missed period by one day.You already missed it by several days.

I think you are Not pregnant as there has been enough time passed for blood test to detect pregnanacy and you got a negative result.Your AF could be late due to stress and thinking.Calm down, and if you want to be sure that you're pregnanat or not and can't wait, you can do this quantative blood test to show HCG level.If the result was < 5 then you are *NOT* pregnanat and you're going to recieve AF soon.

I hope this helped.Good Luck !

iVillage Member
Registered: 09-24-2003
Thu, 10-02-2003 - 4:40pm
Hey thanks for the info. I am still very confused because I am going on 12 days late and I have always been a 28 day girl. With my first 2 babies it was like clock work. I just don't know what to think. Every day I wake up expecting AF, but another day goes by and nothing. Has anyone had a negative blood test and ended up really being preg? I think my doctor just did a normal blood test - not testing any levels of HCG. He just called me and said it was NEGATIVE. Any advice? PLEASE !!!
iVillage Member
Registered: 09-14-2003
Thu, 10-02-2003 - 6:16pm
I just wanted to let you know that my mom had three blood tests when she was pregnant with me and the first two showed negative. (so it is possible) Right now I am going through the same thing, my first blood test came up negative, and the doc wanted to do another test. So two weeks later I am fighting for my results, they were supposed to be in tuesday but I have gotten the run around and no one can keep their story straight (they said they lost them). They were finally found and I am waiting for the doc to call me, which should be any minute.

Good Luck

iVillage Member
Registered: 08-06-2003
Thu, 10-02-2003 - 9:30pm
Don't give up hope. When I was PG with my first I had a neg. blood test and it took another 8 days before it finally came up pos. The only think the dr said was that I must have o'd late in my cycle.Good Luck!