I got a Paragard almost 4 months ago, and things have been good so far. I'm 25 and have never been pregnant, and my insertion went very smoothly. It felt like a couple of bad period cramps and was over before I knew it. I even biked back to work that same day!
After insertion, I had spotting and cramps for a few days. For the next couple of weeks, I had occasional cramps and backaches, but nothing that even required pain killers. Also, my discharge seemed like it was different every day for the first few weeks! That seems to have leveled out, though.
I've had three periods since getting the Paragard, so I've started to notice some patterns. I start getting a stringy brown discharge a few days before my period starts. I start getting cramps a few days beforehand too, although with each passing month, the cramps have started later and later. My period now starts with a few light days, followed by 1-2 heavy days, then another string of light days. The first two were 10 days long, while the most recent one was 14 days (I hope it doesn't stay that way!). My period is certainly longer than it was before getting the Paragard, but even the heavy days aren't any heavier than before. The cramps I get now are somewhat different than what I used to experience. My cramps used to be a dull ache/nausea that would usually last for the first two days of my period. With the Paragard, my cramps are more like a sudden stabbing pain that lasts for a few seconds and then goes away completely. So on the days when I have cramps, most of the time I don't feel any pain, but occasionally I'll get a nasty stab. I wouldn't say they're any worse than before, just different, and the number of days I've had cramps has gotten smaller with each passing month. I wouldn't complain if my periods went back to their old length (about 6 days), but the Paragard periods aren't too bad.
Besides periods, the only other change I've noticed is that I seem to have slightly heavier discharge overall. I wear pantiliners some of the time between periods now. I found my strings right away, and they haven't changed at all. I had sex for the first time post-Paragard around the two-month mark, and there weren't any problems there. No pain, and my partner couldn't feel the strings. We still used a condom - it remains to be seen if/when I'll feel comfortable entrusting everything to the Paragard.
Two thumbs up for the Paragard so far!