I have the following data for two different medicines (one currently being used and one new). The data is number of treatments and number of pregnancies

Bemfola - AID (136, 29)

Gonal F - AID (262, 37)

Bemfola - AIH (95, 9)

Gonal F - AIH (150, 11)

The null hypothesis is that Bemfola produces the same amount of pregnancies as Gonal.

I personally compute this to the following for the AID group:

Observed = 29 (the actual amount of pregnancies)

Expected (37/262)*136 = 19 (the amount of pregnancies expected if Bemfola had the same percentage pregnancies)

Chi^2 = 4,99

p = 0,025

But when running it in SPSS I get an entirely different outcome:

Bemfola

Count = 29

Expected = 22,6

Gonal F

Count = 37

Expected = 43,4

Chi^2 = 3,356

p = 0,067

What am I doing wrong?