Help! I'm so confused...

Hey, I wondered if anyone could help me, we've been ttc for 8 months now. On Monday (day 24 of my cycle) I went to the toilet and something plopped out of me into the toilet, when I looked it looked like white/clear tissue, there was also some fresh red blood too. Then i had a bit of spotting for a couple of days, my period is due today and no sign of it yet, has anyone experienced this and any ideas what it could be? I rang my doctor but she was away until next week and its playing on my mind constantly. Thanks