I had my iud removed last week and had a positive blood pregnancy test on monday and a negative on thursday. is there a chance the negative could be wrong? i feel so pregnant but not due for period for another week. what are my odds. i want to be pregnant

Testing too soon: Conception, as defined by the generation of a fertilized ovum, occurs within day or so of the sex. However, it takes about two weeks for the embryo to make enough HCG to produce a positive pregnancy test. Blood test may be done a day after a missed period. Home pregnancy tests should be done 4-5 days after the missed period. If the result is negative repeat the test in 4-5 days. Use first morning urine and follow instructions for the test carefully.