Ok so I've always been on birth control but since I had blood clots in my lungs I can no longer use hormonal birth…

Ok so I've always been on birth control but since I had blood clots in my lungs I can no longer use hormonal birth control. I had my daughter 3 weeks ago and my husband and I just started having sex again. We are using condoms but my question is how effective are they? I've never used them because I've always been on birth control before and I really don't want to get pregnant again. I'm going to look into the copper iud since its non hormonal and lasts ten years...please help.