Progesterone

ok before I get anywhere, I'm from Tennessee and I'm new to this website. Anyways me n my boyfriend already has one child who is 4 years old && also we been trying to concieved baby #2 since 2011 && after that we find out I was pregnant with baby number 2 in May 2015 well in June 2015 I lost him/her and I knew there was something wrong when all the dr tests and blood test and scans were negative again and they couldn't find anything.  Anywaus the OBGYN dr put me on progesterone to get me to start bleeding again well I started to bleed today and I only have one pill left and I called my OBGYN nurse and talked to her while she was at the OBGYN today and she said that I need to take it to get my cycle back to normal but I have never had a regular period I have irregular periods so my periods are not the same every month.   

 So my question is will I have any issues trying to get pregnant again? After I take the last pill? I go back next Tuesday to my dr so I will get more answers but I am trying to understand how this pill works it's the off white yellow pill and all I know is that its a hormone pill and can also Be used for pregnancy.  

*have a 4 year old daughter name Athena, conceived baby #2 in May 2015 and lost him/her in June 2015 I had a chemical pregnancy