quick question

I just had my daughter 4 months ago and I'm starting to be sensitive to smells and my stomach has been crampy like it was before I knew I was pregnant with her. My question is Can you conceive a day or two before you get your period? We weren't trying for a baby so I wasn't charting. We also weren't preventing lol I'm just not sure if it's possible or not. Before my 4 month old was conceived I ovulated the week after my period not a few days before. I'm just not sure if I'm paranoid or what. 😩