Positive home pregnancy test on Friday, March 29, line was very faint, but visible. Lady night, (Wednesday, April 3), spotting, pink to dark red, no pain. HCG levels 25mIU at hospital, nothing on US. Today, dark red spotting, with clots, heavy only when I sit on the toilet. Still no pain, no cramping. Slight nausea. Professional opinion: miscarriage, implantation and I miscalculated my dates (my math from LMP put me at 5 weeks), or something else?