Home pregnancy tests today will typically test positive at 25-50 ml. Average hcg levels at 4 weeks (that's 4 weeks since last menstrual period) are 100. Even accounting for late implantation or late ovulation, by 5 or 6 weeks last menstrual period, there is no way you should test negative on a home pregnancy test. To do so would mean either the test is defective or levels are too low to sustain, or the test was not properly used.
HCG (which is what these tests run off of) must be present in order for a pregnancy to be viable. They typically rise from 60% to double every 48 hours or so. HCG is found first in the blood, then metabolizes into the urine.
I'm giving you this info just so you know what a test is looking for. No HCG means no pregnancy. At this point the best thing to do would be to see your Dr. for a blood test. That will give you 100% sure results.
With my first I came off the pill after being on it for 10 or so years. I thought it would take us months to conceive as I'd not had a period for a long time (unexplained). Was feeling a bit under the weather so did a test and found out I was 5+ weeks. Turns out I would have been 8+ weeks at that point thanks to the new date I got at my first scan. I would have conceived within a week of being off the pill. We were ready for it this time round! :-)
I didn't know with most of mine until nearly 4 weeks, because my children all happened on Depo. lol. This pregnancy we wanted so we were checking every 2 weeks but prior to that it was 12-14 weeks before I knew. I'm not sure why I guess sometimes life consumes you and you just don't realize the signs are what they are.
I have a family member about to deliver that was 15w until she found out. She had something like her pd on time every month and was going thru some stress in her life so never thought she was pg until missed a cycle all togather.
With my first I was 10 weeks when I found out. With the baby I lost a year ago, I was 12 weeks when I found out.
Yes I'm 22 and have two kids I dint find out with my son tell I was almost 3 months because home test wouldn't work its due to your hcg not being high enough for home test to pick up but most doctors won't even see u tell your between 8 to 10 weeks pregnant anyways :)