Anyone know what this is

im 22 weeks pregnant and a few weeks ago I had little bits of blood when I wiped and slight pain, I rang my midwife and she said to keep an eye but its no cause for concern. anyway it stopped but now for the past 4+ days I've had excessive discharge and sometimes have had tiny tiny blood clots and pink discharge. I get really bad lower back pain but I've put it down to baby's position, I sometimes get shooitng pains in my lady parts but female friends have said its normal I'm a ftm so I'm abit new to this. I'm just curious as what it could be?