Cycle changing - ???

So I have a 16 month old daughter and before having her I always had shorter lighter periods like 5 days long and only one day was really heavy... I got my period back when she was 6 months old and was regular since then up until 2 cycles ago. It was pretty heavy and crampy, they lasted a good week plus spotting before and after and I was super moody around them... then 2 months ago it did a 180 and I’m less moody and my cycles are now 3-4 days long and really light the whole time. Like heavy spotting one day and spotting the other 2-3. Is this normal? Am I just lucky? We do want one more child so I’m nervous I’m getting menopause at 35 or something is wrong... I’m still 10-15 pounds away from my pre-pregnancy weight and feel good! Just thought I’d ask if anyone else has experienced this! Thanks