Good evening, we've been planning our third child for two years and it…

Good evening, we've been planning our third child for two years and it hasn't worked out yet, we've seen doctors who have given us good news, our cycle has minor irregularities, there were two pregnancies and they were completely different. I'm going to focus on the main thing, I'll be off work for two days, and for two days my nipples hurt, one day they feel normal by evening but then they ache, and so on for two days, there is a pulling sensation in the lower abdomen, this morning there was brown discharge, I thought that the period would come but nothing happened, but the abdomen still hurts, there is no strength, could this be implantation? ?‍♀️