False positive? Faint positive hpt followed by 5 negative tests within a week

[Julez0417]

Hi there!
I am new to this and am seeking some insight as I've racked my brain googling and stressing over this.
I'm 27 with no previous medical conditions. My husband and I have been trying to start our family. My last period started May 26th (was one day late). On June 23rd (3 days before my next period was due, I started thyroid meds per my doctor to bring down my TSH levels. Later that day, I had some very light spotting/bleeding (pinkish/brown)- it lasted less than 12 hours.

I have had no spotting since, some nausea, fatigue and then severe stomach pain kicked in on June 27th.
I went to the Dr who did a urine test & blood test to test for pregnancy, they were both negative.
The stomach pain became intermittent & went away within a day or two. I've still had moments of nausea, backaches and fatigue.

On July 7th, I took a pregnancy test & it came back positive! :) :) The 2nd line was slightly faint but showed up immediately! We were beyond elated. I wanted to take another test in hopes of getting a more positive result before calling the doctor on Monday. Well since the 7th, all the hpt's have come back negative with not even a faint positive line.
We've become a bit disheartened and confused by this. I've been googling so many things trying to determine if it's possible that we got a false positive and all other possibilities.
Anyone have any advice of what could be happening? Could I really be pregnant if all these tests are now coming back negative? If so, shouldn't my hcg levels raising enough to show on the tests?

Thank you so much!

[specialmom]

Gosh, that's confusing!  False positives are kind of rare.  Things that can cause them are not reading the test at the right time.  Tests can sit and develop a second line that looks like pregnancy but is really an evaporation line.  I'm assuming you didn't do that.  If you had what is called a chemical pregnancy which is a really brief time of pregnancy and an immediate miscarriage (which is usually around when you'd get a period).  Medications can interact.  I don't see thyroid medication listed but the thyroid does involve hormone function so that would be a possibility.  I personally would call your doctor about it anyway, even if you got another negative.  Two positives and newly on thyroid medication warrants a discussion with your doctor.  Let me know what they say.