I just found the liner to be a comfort, you can get a bit of "leakage" when you first get up... I didnt need a pad.
As for me, I started using them due to bleeding at 6 weeks, and I am now 20 weeks. I used them till after my 12 week scan.
As for side effects it is a nautral progesterone, so you might get things like tender bbs, bloating and the usual pmt stuff. I found it hard to tell cause I was pg...
hope this is the ticket for you hun!