I Take Lasix On A Regular Basis, 40mg Daily, And

I take lasix on a regular basis, 40mg daily, and benadryl for allergies at bedtime, and I am currently 2 days late based on my period cycle...I have taken 2 at home pregnancy tests, both negative, because of symptoms...especially spotting during implantation period, and unprotected intercourse during my fertile time of month, and ovulation day...first test was a day before missed period, second test, taken yesterday, day 2 of missed period...could my hcg levels just be too low still, due to lasix or other meds, and getting false negatives...what to do? Please???