hi my last period was due on thursday july 19th but i started on the friday 20th on my 1st day im normaly light but this one was heavy then light on day 2 then stopped completely im always every 27 days and ast for 4-5 days is it possible i may be preg i did do a test day b4 my bleed but neg at the time not done one since my partner and i are ttc since dec ????