I have just had to wait the longest 3months after having methrotrexate! You're not allowed to ttc within 3mintgs of the treatment for ectopic. It was my 2nd ectopic (one in 2012&2014). However tests have shown no reason, I've never had an infection and I've got no blockages or scaring and luckily I still have both tubes so it would seem that it's just really really bad luck for me to have 2 :(