Understanding Early Pregnancy: Ultrasound & Home Pregnancy Test Results

Question
My girlfriend and I are trying to have a baby. She had a normal menstral cycle on 3/19/08 we tried on 3/25/08, 3/27/08, and 3/30/08. On 4/1/08 she had unltrasound done after complaining of stomach cramps. They could not find any signs of her being pregnant. On 4/10/08 she took HPT and it showed neg. On 4/13/08 took HPT Faint positive. On 4/18/08 took another HPT again Faint positive. On 4/17/08 she started a period very light bleeding and only lasted for day and half. On 5/12/08 she saw an OBGYN and took a urine and blood pregnancy test. Urine showed positive blood showed negative. Today 5/17/08 she told me that she started a period heavy flow. She has symptoms and signs of pregnancy. Nausea from certain smells etc. Vomiting, Complains of pants not fitting. says she feels pregnant but then doesn't. She is scheduled for another visit with the OBGYN on 5/22/08 for an ultrasound to confirm visually a pregnancy. We have not had intercourse sense 3/30/08. She has also been taking an anti-biotic called Erythomycin, which OBGYN thinks maybe causeing some of the symptoms of pregnancy. Could first ultrasound have been to early to see anything? Could she be pregnant or is it just side effects of the anti-biotic? Some help please. James

Answer
Dear James,

The nausea and vomiting and sensitivity to smells could certainly be attributed to the antibiotic. If she had a regular period on 3/19 and has regular 28 day cycles, she would have been expected to ovulate and be most fertile on 4/2 (and the couple days before). So the only date of unprotected sex that would be considered to have taken place right around ovulation would have been on 3/30. A 4/1 ultrasound would have been before ovulation would likely have even taken place that cycle, so yes, it would have been too early to note any possible pregnancy.

If conception did take place from the 3/30 encounter, 4/13 would have been pretty darned early to get a positive from a HPT, but I suppose not necessarily impossible. And typically the blood test results are much more conclusive than urine test results. If she had conceived on 3/30-4/2, she would have been approximately 7 weeks, 5 days along when the testing was done on 5/12. By that time, the hCG level of a healthy pregnancy would have been 7,650 - 229,000 mIU/ml - well over the 25 mIU/ml mark need to get a positive reading.

Unfortunately, I would suspect that the ultrasound on 5/22 will not show evidence of a healthy pregnancy since the blood test came back negative and she is experiencing a heavy, period-type bleed now.

I hope this has helped you and answered your question. I wish you well.

Brenda