When we is the earliest I can test

Hi ladies. So my period has been coming every 5 weeks since it came back from breastfeeding my daughter who's 14months and still feeding 2/3 times a day. I ovulated on 29th July and my period is expected to come on the 12th of August. When is the earlier I could test. Also not sure if breastfeeding is messing with my ovulation if that's even possible?