Using a GSM shield with LCD03, Serial communication errors I believe

Hey guys i am doing a gas alarm system incorporating a Sim900a gsm module, an mq6 sensor and an LCD03. What it should do is, when subjected to a LPG send an sms to a mobile phone.

When i add the commands for the LCD03, the project stops working. I am wondering if it is because i am using serial communication to use the ports 9 and 10 for Rx,Tx to my GSM shield. And the LCD03 is connected to SDA and SCL which are also Tx and Rx. Would that cause the shield to stop sending the message?

Even if the lcd is not connected this problem persists.

#include <SoftwareSerial.h>
#include <Wire.h>
#include <LCD03.h>

SoftwareSerial mySerial(9, 10);

int sensor=7;
int speaker=8;
int gas_value,Gas_alert_val, Gas_shut_val;
int Gas_Leak_Status;
int sms_count=0;

void setup()
{

pinMode(sensor,INPUT);
pinMode(speaker,OUTPUT);
mySerial.begin(9600);   
Serial.begin(9600);
lcd.begin(20, 4);
 lcd.backlight();
}

void loop()
{
CheckGas();
CheckShutDown();
}

void CheckGas()
{

lcd.setCursor(0,0);
lcd.print("Gas Scan - ON");
Gas_alert_val=ScanGasLevel();
if(Gas_alert_val==LOW)
{
 SetAlert(); // Function to send SMS Alerts
}}

int ScanGasLevel()
{
gas_value=digitalRead(sensor); // reads the sensor output (Vout of LM35)

return gas_value; // returns temperature value in degree celsius
}

void SetAlert()
{
digitalWrite(speaker,HIGH);  
while(sms_count<3) //Number of SMS Alerts to be sent
{  
SendTextMessage(); // Function to send AT Commands to GSM module
}
Gas_Leak_Status=1; 
lcd.setCursor(0,1);
lcd.print("Gas Alert! SMS Sent!");
}

void CheckShutDown()
{
if(Gas_Leak_Status==1)
{

Gas_shut_val=ScanGasLevel();
if(Gas_shut_val==HIGH)
{

lcd.setCursor(0,1);
lcd.print("No Gas Leaking");
digitalWrite(speaker,LOW);
sms_count=0;
Gas_Leak_Status=0;
}}}

void SendTextMessage()
{
  mySerial.println("AT+CMGF=1");    //To send SMS in Text Mode
  delay(1000);
  mySerial.println("AT+CMGS=\"+919495xxxxxx\"\r"); // change to the phone number you using 
  delay(1000);
  mySerial.println("Gas Leaking!");//the content of the message
  delay(200);
  mySerial.println((char)26);//the stopping character
  delay(1000);
   mySerial.println("AT+CMGS=\"+918113xxxxxx\"\r"); // change to the phone number you using 
  delay(1000);
  mySerial.println("Gas Leaking!");//the content of the message
  delay(200);
  mySerial.println((char)26);//the message stopping character
  delay(1000);
  sms_count++;

and an LCD03

What IS an LCD03?