Looking for help/advice

Joanna
Hi there,
I've been on the app for about 4 months but never posted before so this is my post.
I'm about to turn 32. And I have one child age 8 with a previous partner and me and my boyfriend are now trying to conceive our first lovely bundle of joy. 
As soon as I had my son I had a contraceptive rod put in and had this replaced 2 times for a total of 8 years and had this taken out at the beginning of the year. Although I had a son before this was never a bed and I fell pregnant so have never actually tried for a baby which is new and exciting. 
I had some endometriosis removed in December that was causing me discomfort but this was before we were trying to conceive. And the operation was a success. 
I only have one Fallopian tube but since I had the rod out I have been testing to see if I'm ovulating and it returned almost straight away. I wee on the sticks and get the two strong lines and this usually happened two days in a row.
So far I have ovulated 3 times - the last positive ovulation twats showing on the 11th and 12th of this month (so 8-9 days ago.).
Yesterday I had a small brownish stain about the size of a 5pence piece. And when i wiped there was some discolouration but not much. And that was it nothing more. I thought I was going to get my period early as I had some small pains but that's it. It went and also It would have meant I was at least 5 days early which has never happened.
So anyway, I just wondered if I should be worried as im doing everything to the letter and looks like I'm probably going to get my period again. Can anyone recommend anything or is this normal for 30's or maybe just case I have one tube? Is that brownish stain likely to be anything else? I took a test and it was negative (again!)
Thanks for your time and sorry for the long post! X