Hi,I Am 36 And I Had Low Vit D And

Hi,I am 36 and i had low vit d and thyroid levels were abnormal, one of the internist put me on thyroxine 50mg, and vit d supplementation , and in 1 months time my blood showed normal results. I am on this medication for the last 2 months.
I am planning to conceive and in the last 30 days , i missed my cycle last month and also am having severe nausea, with on and off lower abdomen muscle cramps. This nausea is so severe that i am unable to focus on any other works and also having dizziness once in a while, which is scaring me to step out of the house. Consulted a gyno, she said, its too early to say if the symptom is related to being conceived, Now just yesterday, i see spotting and today regular flow is shown.
I did urine test for pregnancy twice earlier and it showed negative. Now in this scenario, I don't know if i am pregnant and still my cycle is on ( under assumption of implantation bleeding) , and this nausea is constant, with severe lower abdominal cramps.

Kindly suggest me what s my current status and what am I going through and what has to be done further. I have done all my blood tests 30 days back and all the reports were W N L ( Within Normal Limits).