PLZ HELP!!!!

I'm so lost and confused... My husband and I have been married for 2 years. We have tried and tried for a baby. Last year I became pregnant... Not long after I had a misscarage. My periods used to be normal with no problems. Sense my misscarage my periods haven't been the same. I was put on a depo shot last year sometime untill my husband and I decide to try for anotjer baby. I have been off of the shot for more then 10 months. We have been trying and trying and trying. One month my period cycle is every 31 days. Next month its every 38 days. I think I am pregnant so i test and test and test to find out my period was just late. I don't know my period cycles or my ovulation times. My husband and I want a big family. I am 25 and he is 28. We want at least 5 kids... But with what's all going on idk... My husband and I had sex 3 times in one day, it is 8 almost 9 days sense we had sex last. This evening I went to the bathroom and when I wiped there was a little brown discharge. Idk what it is... Is it pre period or what?!... 😔😣