Thank you for your query.
It seems as if you have again suffered an early pregnancy miscarriage
That could explain the very weakly positive urine test, but a negative blood test
Just to be on the safer side, a repeat B HCG blood test after a week would confirm if there IS a pregnancy.
I need to have more details regarding your miscarriages to comment.
There could be genetic causes, autoimmune disorders
, uterine abnormalities in size and shape , intra uterine infections, hormonal imbalances etc.
Also, the details of the time of previous abortions, to know exactly if you have a problem in conceiving as well.
If you do have issues regarding fertility
, ovamit or clomiphene
is often given to help ovulation and conception.
However there are various aspects to fertility like semen count, tubal patency, hormonal status etc.
Based on what you have provided, it is difficult to opine.