i understood your problem...your periods were regular till march 8,,since then you did not had period...so its been nearly 4 months since last period...
are you tubectomised(family planning operation),or using contraceptives??
when was the pregnancy
test done at home,,and by gp....is it may 15th?(cant be march 15 as you had period in march)
and you said weakly positive?.(sometimes false positive).did not bleed at all since then...if you were pregnant you could have realised by now by external appearance......so unlikely to be contiuing pregnancy now..
do not worry..there can be many reasons for delayed or mised periods (harmonal,uterine fibroids molara pregnancy,sress etc)...to confirm get urine pregnacy test with first early morning sample,,blood beta hcg
levels,usg abdomen(this will confirm your problem if any)..consult gynaecologist,,and follow her treatment,,,
you will be normal very soon,,bye