Jangan risau too much, dear, when you are still nursing, your cycle can be really unpredictable, so a late period by a few days is not unusual at all. Breastfeeding naturally suppresses the hormones that control ovulation, so even after your period returns, it can still be irregular for quite a while. That said, since you have been intimate with your husband and you are feeling that sharp pain on your left side, I would honestly say please do not wait, take a test today, because that kind of one-sided pain can sometimes need prompt attention. Do check with your doctor as soon as you can, especially about the sharp pain, as it is always better to be safe and get a proper examination rather than worry on your own. Wishing you all the best, dear!