Here's a question for you ladies...

[southernmommie]

I have the pregnancy pee strip tests. The ones you have to pee in a cup and then dip the stick in it. I rinsed my cup out really really well, like really well. A friend came over and she thinks she is pregnant too. So I offered her to take one of my strip tests. I buy a bunch off of amazon for cheap. She used my cup that I used 3 days previously. Her test came up positive but not as dark and fast as mine. So I gave her some more to take home. She took another one this morning and it came up negative. Is it really possible for her to get a positive pregnancy test from using my cup with rinsing it out so many times??

[JennJenn84]

I wouldn't rule that out, but I can't be for sure. Did you just rinse it or did you actually wash it?

[scruffy too]

I would be very surprised if that was the case.  Even if you only rinsed the cup, and not washed it, we're talking TRACE amounts of pee that would instantly be very diluted in her own urine.

[southernmommie]

rinsed, but we're talking about like 5 or 6 times really REALLY well. And then set it under the cabinet upside down to dry over a body spray bottle I don't use. I still think she is pregnant. she's two weeks ahead of me if she is unless my own dates are wrong, which is possible. That is just so hard for me to believe that it's because of my pee.

[LilyTiger]

What sounds more likely is a chemical pregnancy, meaning that the embryo (or zygote or blastocyst or whatever it is that early on) fails to implant all the way or implants and then is rejected because it is non-viable.  Many doctors advise women not to test too early because such non-viable embryos are pretty common and can give women false hope.  They'll get a positive test result and then a negative result a few days later as hormone levels drop back down.  Most women have such chemical pregnancies but don't know about them either because they're not testing or because their testing misses the brief "positive" period and only catches the negative that follows.  If it is a chemical pregnancy, she'll probably get her period in the next week or so.

(Someone with an anatomy and physiology background could tighten some of this up, but if you actually rinsed the cup thoroughly, I don't see how enough HcG would be hanging around for her to get a false positive)

[skycheattraffic]

FWIW I got a faint positive in the evening, then a negative with my morning pee. I went to see my Dr and had a blood test that confirmed I was indeed pregnant. I was about 4.5 to 5.5 weeks along; definitely past my expected date for AF. The tech that drew the sample had worked in reproductive care and explained that the urine tests may come up negative if tested outside a certain window - too early or too late. I'm not saying the test is wrong but I encourage you both to get the blood test done if you suspect you're pregnant. As far as I understand, the blood test is very definitive. Hth

[1babysmom]

Originally Posted by skycheattraffic 

FWIW I got a faint positive in the evening, then a negative with my morning pee.

I was going to mention something along this line...I always get my first positives in the evenings, and the morning one the next day is generally barely there! (but darker again that evening)

[dayiscoming2006]

She should take another test if she hasn't gotten her period/miscarried in a day or 2 and see if it comes out positive. I think it was a real positive. There's no way it could have been from you.