It’s difficult to ask for advice about this without sounding totally neurotic and well crazy. Firstly I’m not trying to conceive, and don’t know how I will feel if I am pregnant. I’ll be happy if I am, but I think I’ll be more happy if I’m not – more than anything I just want to KNOW for certain.
So my story – I’m 29 and I had cancer almost 6 years ago (went through radiation and chemo). Have been fine ever since, no medication at all. I have never been on any kind of birth control and have a 27 or 28 day cycle since I was 13. My period always lasts for 5 days fairly heavy bleeding, with a day of spotting after.
The last couple of months have been odd. My last normal period was 7 weeks ago. I had sex with my bf 2 days before I ovulated (I get ovulation pain, so know when it happens). When my period was 2 days late I took a hpt and got a bfn. The next morning I had normal period pains and started what I thought was my period, except it was much lighter than usual (but still more than spotting). I used 1 pad throughout the day, and a regular tampon overnight (I usually soak several super plus tampons per day). The bleeding lasted 2 days and then I spotted for another 2. I was feeling exhausted all the time and with a weird period I went to my gp and asked for a blood test. It came back negative (this would have been 18dpo). So I knew I wasn’t pregnant, but I was getting more and more symptoms of being pregnant. I had a follow up appointment with my oncologist anyway, so I told him what was going on and he sent for another blood test (and other blood tests). The test came back negative (23 dpo). He sent me for more tests all were normal, so I don’t have cancer (YAY)

, and then sent me to a specialist physician to figure out what’s causing my symptoms. He sent me for an ultrasound and now they are saying that pregnancy can’t be ruled out because some people don't test positive and the scan was inconclusive (endometrial thickness and size of uterus where in line with a 6 week pregnancy, but no gestational sac could be seen – but they only get reliable readings at 8 weeks with an external scan). I’ll get my full hormone profile back on Monday, but the first appointment I could get for another scan is almost 4 weeks away which is just TORTURE!!!
Now people keep telling me about how they tested negative for the first few months. My friend had her baby last week, and she said she was 7 weeks before she got a positive with him, and she had a miscarriage before him at 8 weeks and never tested positive until she went to the ER with heavy bleeding. My mom also had negative tests and periods for the first 2 months with my brother, but that was 25 years ago and she can’t remember if they were blood tests.
So after making you read through my whole long history… here’s my question:
1) Have any of you ever tested negative on a blood test (I think mine were qualitative) and later tested positive? And if so when was your last negative? And when did you finally test positive? What explanation did they give you?
2) How do you all you all cope with the not knowing and just “forget” about it when you feel this ill all the time?
Sorry that this is so long.

I'd appreciate any advice you can give me.