Husband confused 🤔

Ok so me and my wife are trying for a baby. I'm 35 she is 45... Her period came October the 4th on a Thursday and went off October the 8th the following Tuesday. We had sex the next day and sex a couple times after that, cant be sure of the days. Anyways about a week after her period went off she started spotting when she wipes a light pink color and had a bad cramping one night and she said like a lingering light cramp the next day. The spotting lasted about 3 days, and on the 4th day no spotting just a lil brownish colored on her panty liner. She told me her breast on the outer edges are sore or tender. She has a 28 day cycle. Could anyone give me some light on this. I really want a baby and its driving me nuts she's having these symptoms. Could she be pregnant a week after her period and if so could it be implantation bleeding?